SYSTEM  OF  LOGIC, 


COMPKISING 


A  DISCUSSION  OF  THE  VARIOUS  MEANS  OF  ACQUIRING  AND 
RETAINING  KNOWLEDGE,  AND  AVOIDING  ERROR. 


BY  p.  MCGREGOR,  A.M. 


NEW  EDITION,  REVISED. 


NEW    YOEK: 

HARPER  &  BROTHERS,  PUBLISHERS, 

FKANKLIN    8QUAEE. 

1872. 


Entered,  according  to  Act  of  Congress,  in  the  year  one  thousand 
eight  hundred  and  sixty-two,  by 

HARPER  &  BROTHERS, 

In  the  Clerk's  Office  of  the  District  Court  of  the  Southern  District 
of  New  York. 


f 


PREFACE. 


THE  following  treatise  is  the  result  of  an  attempt 
to  comprise  within  moderate  limits  everything  of 
general  interest  which  properly  belongs  to  Logic,  free 
from  prolixity,  obscurity  or  misrepresentation.  Much 
that  occurs  in  other  works  on  the  same  subject,  has 
been  rejected  as  useless,  irrelevant  or  erroneous,  while 
I  have  endeavored  to  supply  numerous  deficiencies, 
and  to  exhibit  a  clear  and  accurate  view  of  the  prin- 
ciples and  processes  of  logical  thought,  divested  of 
scholastic  figments,  which  only  perplex  and  mislead 
the  student. 


M114677 


CONTENTS. 


INTRODUCTION. 

PAGE 

§  1.  Nature,  Foundations,  and  Limits  of  Logic 13 

§  2.  Objects,  Uses,  and  Study  of  Logic 14 

§  3.  Advantages  of  Knowledge,  and  Evils  of  Ignorance 15 


PART  I. 

OF  THE  ULTIMATE  SOURCES  AND  ELEMENTS  OF  KNOWLEDGE,  AND 
THE  PRIMARY  PROCESSES  BY  WHICH  IT  IS  ACQUIRED  AND  RE- 
TAINED. 

CHAPTER  I. 

A  GENERAL  VIEW  OF  THE  LIMITS,   DIVISIONS,  AND  IMMEDIATE 
SOURCES    OF    KNOWLEDGE. 

§  1.  Necessary  Limits  and  principal  Divisions  of  Knowledge 29 

§  2.  Of  the  various  Faculties  by  which  Knowledge  is  acquired 

and  retained 32 

§  3.  Of  Propositions.... 37 

§  4.  Of  Probability 40 

§  5.  General  Criterion  of  Truth,  and  immediate  Source  of  Error  45 

CHAPTER  II. 

OF     REASONING. 

§  1.  Nature,  General  Principle,  and  Expression  of  Reasoning  ...    49 

§  2.   Special  Principles  of  Reasoning 52 

§  3.  Processes  and  Criterions  of  Reasoning G5 

CHAPTER  III. 

OF  THE  PRIMARY  MEANS  OF  ACQUIRING  CONTINGENT  KNOWLEDGE. 

§  1.  Reality  of  Apprehensions,  and  Means  of  avoiding  the  pri- 
mary Errors  which  they  directly  occasion 71 

§  2.  Primary  mental  Processes  by  which  contingent  Knowledge 

may  be  acquired ; 75 

§  3.  Primary  external  Processes  by  which  contingent  Knowledge 

may  be  acquired 86 


vi  CONTENTS. 

CHAPTER  IV. 

OF   THE   PRIMARY  MEANS    OP   RETAINING   KNOWLEDGE. 

PACK 

§  1.  Reliability  of  Memory,  and  Means  of  avoiding  the  primary 

Errors  which  it  tends  to  produce 93 

§  2.  Primary  Processes  by  which  Knowledge  is  retained 96 

CHAPTER  V. 

OF   GENERALIZATION. 

§  1.  Nature  of  Generalization 98 

§  2.  Principal  Processes  of  Generalization 99 

§  3.  Extension  and  Uses  of  Generalization 107 

CHAPTER  VI. 

OF    HYPOTHESES. 

§  1.  Nature  and  Uses  of  Hypotheses 109 

§  2.  Methods  of  testing  Hypotheses 113 


PART  II. 

OP  THE  PRINCIPLES  AND  METHODS  OF  INVESTIGATION. 
CHAPTER  VII. 

OF  INVESTIGATION  IN  GENERAL. 

§  1.  Of  Dispositions  affecting  Investigation 119 

§  2.   Of  Habits  affecting  Investigation 121 

§  3.  Of  Things  which  require  no  Proof 127 

§4.  Of  Things  which  may  generally  be  admitted  as  proved 129 

§  5.  General  Modes  of  determining  the  Validity  of  Proofs 134 

CHAPTER  VIII. 

OF   STUDY. 

§  1.  Nature  and  Uses  of  Study 139 

§  2.  Subjects,  Modes,  and  General  Rules  of  Study 140 

§  3.  Selection  and  Study  of  Books 148 

CHAPTER  IX. 

OF   ORIGINAL   INVESTIGATION. 

§  1.  General  Character,  Uses,  Prerequisites,  and  Methods  of 

Original  Investigation 151 

§  2.  Of  Direct  Discovery 155 

§3.  Of  Indirect  Discovery 156 

8  4.  Of  Invention 162 


CONTENTS.  vii 


CHAPTER  X. 

OP   CAUSES   AND   EFFECTS. 

§  1.  Sources  and  Applications  of  the  Knowledge  of  Causes  and 

Effects 165 

§  2.  Various  Kinds  of  Causes 169 

§  3.  Methods  of  determining  Causes  and  Effects 171 

CHAPTER  XI. 

OF    LANGUAGE. 

§  1.  Origin  and  Progress  of  Language 182 

§  2.  Uses  of  Language 189 

§  3.  Imperfections  and  Abuses  of  Language 194 

§4.  Interpretation  of  Language 200 

CHAPTER  XII. 

OF     EVIDENCE. 

§  1.  General  Principles  of  Evidence 209 

§  2.  Criterion^  of  Testimony 212 

§  3.  Various  Kinds  of  Testimony,  and  Peculiarities  of  each 226 

§  4.  Means  of  ascertaining  the  Origin  and  Character  of  Written 

Testimony 228 

CHAPTER  XIII. 

OF     CLASSIFICATION. 

§  1.  Nature  and  Uses  of  Classification 238 

§  2.  Principles  and  Methods  of  Classification 240 

CHAPTER  XIV. 
Tabular  View  of  the  Means  of  acquiring  Knowledge 246 


PART  III. 

OF    FALLACIES. 
CHAPTER  XV. 

NATURE   AND   CLASSIFICATION   OF   FALLACIES. 

§  1.  Nature  of  Fallacies 249 

§  2.   Classification  of  Fallacies 250 

CHAPTER  XVI. 

SOURCES   OF   FALLACIES,  AND  MEANS    OF   GUARDING   AGAINST   THEM. 

§  1.   Sources  of  Fallacies 252 

§  2.  Of  Prejudices 254 

§  3.  Means  of  guarding  against  Fallacies 260 


viii  CONTENTS. 

CHAPTER  XVII. 

OP  PARALOGISMS,  OR  FALLACIES  OF  PRIMARY  ASSUMPTION. 

TAOK 

§  1.  Paralogisms  of  Intuition 2GG 

§  2.  "  assuming  what  is  attempted  to  be  proved....  2G7 

§3.  "Comprehension 2G9 

§4.  "  "Signs 271 

§5.  "  "Memory 274 

§  G.  Intrinsic  Paralogisms  of  Testimony 275 

§  7.  Extrinsic  "  "  280 

§  8.  Paralogisms  of  Misinterpretation  of  Language 283 

CHAPTER  XVIII. 

OF    SOPHISMS,  OR   FALLACIES    OF    INTERMEDIATE    REASONING. 

§  1.  Sophisms  of  Confusion 287 

§2.          "          "Generalization 289 

§3.         "          "Causation 292 

§4.          "          "Probability 298 

CHAPTER  XIX. 

OF  ABERRANCIES,  OR  FALLACIES  OF  IRRELEVANCY. 

§  1.  Aberrancies  of  Confusion 306 

§2.  "  "  Appeals  to  Authority 316 

§3.  "  "  Appeals  to  Desires 320 

CHAPTER  XX. 

Table  of  Fallacies...,  ..325 


PART  IV. 

A  SPECIAL  SURVEY  OF  THE  PRINCIPAL  BRANCHES  OF  KNOWLEDGE. 

CHAPTER  XXI. 

CLASSIFICATION   OF   KNOWLEDGE,  ACCORDING   TO   ITS    SUBJECTS. 

§  1.  Scientific  Knowledge 331 

§2.  Mixed  "          339 

§  3.  Particular         "          340 

§  4.  Tabular  View  of  Knowledge 341 

CHAPTER  XXII. 

OF    MATHEMATICS. 

§  1.  Peculiarities  of  Mathematics ' 344 

§2.  Uses  "  "  346 

§3.  Study  "  "  347 


CONTENTS.  ix 

CHAPTER  XXIII. 

OF  THE    PHYSICAL   SCIENCES. 

PAGE 

§  1.  Of  the  Physical  Sciences  in  general ..  351 

§2.       "      Mechanical  Sciences 352 

§3.       "      Ethereal  "       358 

§4.       "      Organical  "       362 

§5.       "      Geographical     "      367 

CHAPTER  XXIV. 

OF   THE    MENTAL    SCIENCES. 

§  1.  Of  the  Mental  Sciences  in  general 374 

§  2.  Of  Logic  and  Psychology 376 

§  3.  Of  Theology 377 

§  4.  Of  Morality,  or  Ethical  Science 381 

§  5.  Of  Jurisprudence 383 

CHAPTER  XXV. 

OF   MIXED   KNOWLEDGE. 

§  1.  Of  Philology 385 

§  2.  Of  Ethnography 391 

§  3.  Of  Technology 392 

CHAPTER  XXVI. 

OF   PARTICULAR  KNOWLEDGE. 

§  1.  Of  History 396 

§  2.  Of  Chronology 402 

§  3.  Of  Biography 403 

CHAPTER  XXVII. 

OF   THE   KNOWLEDGE   OF   FUTURITY. 

§  1.  Of  the  Knowledge  of  Futurity  in  general 405 

§  2,  Sources  of  our  Knowledge  of  Futurity 406 


PART  V. 

OF  THE  RETENTION  OF  KNOWLEDGE, 

CHAPTER  XXVIII, 

OF   THE   RETENTION   OF   KNOWLEDGE   BY   SIMPLE   REMEMBRANCE. 

1.  General  Laws  and  Rules  of  Remembrance 413 

2.  Of  the  Relations  of  Thoughts 419 

A  2 


CONTENTS. 


CHAPTER  XXIX. 

OF   THE   RETENTION  OP  KNOWLEDGE   BY  MEANS   OP   EXTERNAL 

SIGNS. 

PAGE 

§  1.  Of  External  Signs  in  general 425 

§  2.  Of  the  Retention  of  Knowledge  by  Writing 427 

CHAPTER  XXX. 

OP   THE   MEANS   OP   POSSESSING   A  READY  COMMAND   OF   OUR 
KNOWLEDGE. 

§  1.  Requisites  to  possessing  a  ready  Command  of  our  Knowl- 
edge   429 

§  2.  Means  of  acquiring  and  employing  the  preceding  Requi- 
sites   431 

CHAPTER  XXXI. 

Tabular  View  of  the  Means  of  retaining  Knowledge 434 

NOTES „...  435 

INDEX 449 


INTRODUCTION. 


SYSTEM   OF  LOGIC, 


INTRODUCTION. 

§  1.  NATURE,  FOUNDATIONS,  AND  LIMITS  OF  LOGIC. — Subjects  and 
Definition  of  Logic. — On  what  founded. — Advantages  of  uniting 
its  three  principal  subjects  in  one  Science. — Why  the  communica- 
tion of  Knowledge  is  excluded. 

LOGIC  is  the  science  which  exhibits  the  foundations 
and  primary  elements  of  knowledge,  the  proper  means 
of  investigating  truth,  the  nature  and  sources  of  errone- 
ous opinions,  the  modes  in  which  we  must  proceed  in 
order  to  secure  the  former  and  avoid  the  latter,  and  the 
best  methods  of  retaining  knowledge  after  it  has  been 
acquired.  It  may,  therefore,  be  defined  the  science  of 
the  acquisition  and  retention  of  knowledge,  and  the 
means  of  avoiding  error.  It  is  founded  on  the  follow- 
ing principles,  the  truth  of  which  becomes  evident  from 
a  slight  consideration  (l).* 

1 .  We  have  only  one  set  of  intellectual  faculties,  the 
laws  of  whose  proper  exercise  are  identical,  throughout 
the  numerous  fields  of  human  inquiry.     Thus  we  have 
not  one  faculty  of  vision  for  Botany  and  another  for 
Chemistry,  nor  one  faculty  of  reasoning  for  Morality  and 
another  for  Geology ;  and,  in  order  to  sound  reasoning, 
the  premises  must  necessarily  imply  the  conclusion  pro- 
fessedly inferred  from  them,  whatever  be  the  subject  of 
consideration. 

2.  Those  faculties  operate  uniformly,  and  are  liable  to 
mislead  us  only  in  certain  ways.     Thus  the  senses  al- 
ways operate  by  impressions  on  the  nerves,  through 
which  corresponding  impressions  are  produced  in  the 
seat  of  consciousness ;  and  they  are  liable  to  mislead  us 
only  by  presenting  something  which  appears  like  a  dif- 
ferent thing.     So  Reason  constantly  operates  by  show- 
ing that  one  thing  necessarily  implies  another;  and  it 

*  The  figures  at  the  ends  of  paragraphs  refer  to  the  notes,  which 
precede  the  Index. 


'14  '  '  "  'INTRODUCTION. 

can  occasion  error  only  by  leading  us  to  believe  that  this 
is  the  case,  when  in  reality  it  is  not. 

The  acquisition  and  retention  of  knowledge,  and  the 
means  of  avoiding  error,  form  subjects  sufficiently  con- 
cise and  connected  to  be  discussed  as  one  science ;  and 
we  throw  unnecessary  obstacles  and  dangers  in  the  way 
of  the  inquirer,  if  we  separate  them,  and,  after  furnishing 
him  with  a  part,  either  leave  him  to  think  he  has  mas- 
tered the  whole,  when  in  reality  he  has  not,  or  tacitly  re- 
fer him  to  some  unknown  quarters,  for  a  knowledge  of 
several  of  its  most  important  parts,  of  which  he  is  still 
ignorant. 

The  propriety  of  including  the  retention  of  knowledge 
will  be  readily  perceived,  by  observing  that  it  is  not  suf- 
ficiently extensive  to  form  a  separate  science,  while  it  is 
essential  to  render  knowledge  available.  In  order  to  be 
of  any  value,  truth  must  not  only  be  discovered,  but  se- 
cured in  such  a  manner  that  we  can  bring  it  before  the 
attention  at  pleasure.  It  is  further  to  be  observed  that 
many  truths  can  be  discovered  only  by  retaining  in  the 
memory  many  others  previously  acquired. 

The  subject  of  the  communication  of  knowledge  should 
be  excluded  from  Logic,  on  account  of  its  great  extent 
and  its  distinct  nature. 

§  2.  OBJECTS,  USES,  AND  STUDY  OF  LOGIC. — General  and  special 
objects  of  Logic. — Its  Utility. — Study  of  Logic. — Who  may  study 
it  successfully. 

Logic  is  designed  to  aid  us  in  every  inquiry,  and  not 
to  dispense  with  any  other  science.  Its  general  object 
is,  to  show  the  capacity  of  our  intellectual  faculties,  and 
the  modes  in  which  they  must  be  employed,  in  order  to 
acquire  and  retain  knowledge,  and  avoid  error.  Its  prin- 
cipal special  objects  are — (1)  to  assist  us  in  determining 
the  truth  of  any  given  proposition  —  (2)  to  guard  us 
against  the  errors  which  we  are  liable  to  adopt,  in  the 
various  departments  of  investigation — (3)  to  furnish  all 
the  other  aids  which  general  discussions  and  directions 
can  supply,  in  the  pursuit  of  knowledge — (4)  to  point 
out  the  best  means  of  retaining  our  intellectual  acquisi- 
tions, so  that  we  may  use  them  at  pleasure — and  (5)  to 
give  us  the  proper  degree  of  confidence  in  our  intellects, 
so  that  we  may  avoid  both  dogmatism  and  skepticism. 

A  man  who  has  ascertained  the  laws  of  proper  inves- 


SEC.  2.]         OBJECTS,  USES,  &c.,  OP  LOGIC.  15 

tigation  and  the  sources  of  error,  will  evidently  deviate 
from  the  paths  of  truth  much  less  frequently  than  one 
who  differs  from  him  only  in  having  paid  no  attention 
to  those  subjects,  and  who  may  consequently  be  led  un- 
awares, by  some  common  prejudice  or  illusion,  into  a 
wrong  path,  from  which  he  would  have  been  restrained 
by  a  knowledge  of  Logic.  To  investigate  some  points 
rightly,  and  to  know  the  nature  and  conditions  of  proper 
investigation,  are  very  different  things,  the  latter  of 
which  is  never  acquired  without  study,  and  can  rarely 
be  acquired  at  all  without  the  aid  of  Logic,  while  it  is 
of  great  value  in  all  the  most  important  fields  of  human 
inquiry. 

The  utility  of  Logic  appears  from  the  fact  that  we  can 
never  adopt  an  erroneous  opinion  without  first  violating 
one  or  more  of  its  principles,  just  as  a  person  cannot 
commit  a  solecism  in  language  without  first  violating 
some  rule  of  Grammar. 

In  order  that  Logic  should  answer  its  objects,  its  prin- 
ciples and  rules  must  be  well  understood  and  remember- 
ed :  for  otherwise  they  will  be  overlooked,  and  conse- 
quently violated,  at  the  very  time  when  their  aid  is  most 
requisite.  Its  various  parts  should,  therefore,  be  studied 
with  such  care  that  there  will  be  no  danger  of  misunder- 
standing them ;  and  the  more  important  parts  should  be 
repeatedly  reviewed,  until  they  are  permanently  impress- 
ed on  the  memory.  The  student  should  particularly  be- 
ware of  adopting  false  views  of  those  rules  and  princi- 
ples :  for,  as  they  are  applicable  to  all  investigations,  he 
will  thus  lay  the  foundations  of  error  on  every  other  sub- 
ject. 

Logic  maybe  mastered  without  any  previous  prepara- 
tion or  extraordinary  abilities  :  and,  therefore,  it  may  be 
studied  successfully  by  any  person  who  will  bestow  on  it 
a  little  care  and  labor,  while  it  requires  much  less  of  ei- 
ther than  some  other  subjects  of  comparatively  little  im- 
portance. 

§  3.  ADVANTAGES  OF  KNOWLEDGE,  AND  EVILS  OF  IGNORANCE. — 
Benefit  of  understanding  the  value  of  Knowledge. — Its  various  Ad- 
vantages: (1)  Its  effects  on  the  main  pursuits  of  our  lives. — Evils 
arising  from  mistaken  views. — How  Knowledge  would  prevent  them. 
— (2)  Its  effects  on  the  Emotions. — (3)  Pleasures  derived  from  it. — 
(4)  Its  influence  on  evil  Habits — (5)  on  physical  Welfare  and  Safety 
— (6)  on  Morality — (7)  on  Impositions — (8)  on  Superstition — and 
(9)  on  mental  Discipline. — Evils  of  Ignorance. — Threefold  Benefit 


1 6  INTRODUCTION. 

of  the  proper  acquisition  of  Knowledge. — Bearing  of  this  section 
on  Logic. 

The  pursuit  of  knowledge  is  often  much  less  pleasant, 
for  the  time  being,  than  that  of  sensual  pleasure,  gain, 
fame,  or  amusement ;  and,  even  when  we  have  engaged 
in  it,  we  are  liable  to  be  led  astray  by  doing  that  which 
is  easiest  and  most  pleasant  at  the  moment.  Hence  it  is 
necessary  that  we  should  clearly  see  the  benefits  which 
result  from  advancing  actively  and  circumspectly  in  the 
right  course,  in  order  that  the  subject  may  receive  prop- 
er attention.  The  following  are  the  principal  advantages 
of  knowledge. 

1.  Knowledge  is  indispensable  to  prevent  us  from  be- 
ing fatally  mistaken,  regarding  the  main  pursuits  of 
our  lives.  For,  in  order  to  this,  we  must  choose  proper 
ends,  and  right  and  judicious  means  of  accomplishing 
them,  while  the  ignorant  cannot  know  what  ends  are 
proper,  or  what  are  the  best  means  of  securing  them. 
The  ends  at  which  he  aims  are  what  particularly  distin- 
guishes a  wise  from  a  crafty  man.  The  latter  often  ex- 
hibits much  ingenuity  and  activity  in  effecting  his  ends : 
but,  as  he  never  sufficiently  considers  the  end,  he  only 
secures  and  accelerates  his  own  ruin ;  and,  the  more  pow- 
er he  possesses,  the  worse  for  himself  and  those  connect- 
ed with  him. 

Striking  instances  of  the  evils  which  result  from  igno- 
rance on  this  subject,  are  furnished  by  the  innumerable 
votaries  of  sensuality,  avarice,  vanity,  and  ambition,  who 
have  formed  a  great  majority  of  mankind,  up  to  this  day. 
They  have  all  thought  themselves  on  the  highway  of 
happiness,  while  they  were  treading  the  paths  of  lasting 
misery.  They  have  erred,  not  only  in  expecting  too 
much  from  their  favorite  objects,  but  in  overlooking 
others,  of  much  more  consequence.  Even  where  the 
general  object  of  their  pursuits  was  proper,  they  have 
erred  egregiously  regarding  its  comparative  importance. 
The  accumulation  of  money,  for  example,  may  be  proper- 
ly sought  by  right  means  and  to  a  reasonable  extent ; 
but  the  case  is  greatly  altered  when  it  is  made  the  para- 
mount object  of  life,  and  pursued  through  right  and 
wrong,  by  men  who  have  paid  no  attention  to  much  more 
important  matters,  of  which  they  are  profoundly  igno- 
rant. 

No  person  knowingly  blasts  his  own  permanent  wel- 


SEC.  3.]         ADVANTAGES  OF  KNOWLEDGE.  17 

fare ;  and  hence  this  is  always  done  ignorantly,  and  if 
the  individual  knew  more,  he  would  act  differently.  Some 
frequently  confess  that  they  are  acting  foolishly :  but  all 
they  mean,  is,  that  such  conduct  is  deemed  foolish  by 
others,  or  that  it  may  possibly  lead  to  some  disagreeable 
consequences,  the  real  nature  and  extent  of  which,  how- 
ever, they  do  not  consider,  and  consequently  do  not  know, 
while  they  think  that  these  will  be  more  than  counter- 
balanced by  the  benefits  which  they  expect  from  the 
course  pursued.  Every  one  necessarily  does  what  he 
deems  best  at  the  time,  upon  the  whole ;  and  hence  those 
follies  arc  inevitably  accompanied  by  gross  ignorance  on 
many  important  subjects,  although  this  is  generally  cul- 
pable, and,  therefore  aggravates,  instead  of  palliating,  the 
guilt  of  their  conduct. 

In  order  to  answer  the  purpose,  knowledge  must  re- 
late to  the  particular  subject  in  hand :  a  knowledge  of 
Mathematics  will  not  supply  the  place  of  an  acquaintance 
with  Physics,  and  much  less  with  Psychology  or  Moral- 
ity, any  more  than  a  superabundance  of  water  will  sup- 
ply the  place  of  solid  food.  In  order  to  permanent  hap- 
piness, which  must  be  the  main  object  of  every  enlight- 
ened mind,  we  must  know  where  it  lies,  and  the  course 
which  we  must  adopt  in  order  to  secure  it.  But  when 
we  have  learned  the  real  nature  and  sure  tendency  of  dif- 
ferent pursuits  and  practices,  we  can  choose  proper  ends ; 
and  a  knowledge  of  our  duties,  and  the  ways  in  which 
these  ends  can  be  rightly  effected,  will  prevent  us  from 
erring  fatally  or  seriously  in  the  pursuit. 

2.  Knowledge  is  requisite  in  order  to  the  due  exercise 
and  regulation  of  the  emotions,  on  which  happiness 
mainly  depends.  The  emotions  are  not  directly  under 
the  control  of  the  Will,  but  are  excited  by  the  contem- 
plation of  their  respective  objects;  and,  consequently, 
these  must  be  perceived  by  the  mind  before  the  emotion 
can  be  excited,  while  the  mind  can  never  perceive  any- 
thing of  which  it  is  totally  ignorant.  Thus  we  cannot 
sympathize  with  the  joys  or  sorrow's  of  others  unless  we 
know  what  they  are ;  and  we  cannot  feel  affection  and 
reverence  for  the  Eternal,  unless  we  learn  those  attributes 
of  his  character  which  alone  excite  these  emotions  to- 
wards him. 

That  happiness  depends  mainly  on  the  due  exercise  of 
benevolent  and  sympathetic  emotions,  and  the  suppres- 


1 8  INTKODUCTION. 

sion  or  eradication  of  those  of  a  contrary  kind,  is  proved 
by  observation,  and  by  the  known  force  of  such  emotions. 
Let  a  man  surrounded  with  all  physical  comforts  and  en- 
joyments only  have  some  strong  malevolent  emotion  ex- 
cited, and  he  immediately  feels  unhappy.  On  the  other 
hand,  let  one  destitute  of  many  of  those  advantages  have 
his  mind  filled  with  strong  pleasant  emotions — regarding 
the  past,  the  present  or  the  future — and  he  is  happy  while 
under  their  influence.  Now  there  are  always  objects 
within  the  reach  of  our  mental  vision  which  excite  such 
emotions :  but  we  must  diligently  search  for  them  and 
keep  them  in  view,  in  order  to  benefit  by  them  ;  and  this 
requires  a  knowledge  of  the  nature  and  importance  of 
those  emotions,  which  are  undervalued  by  the  ignorant, 
because  they  do  not  strike  the  attention  like  objects  of 
sense. 

3.  Knowledge  furnishes  various  direct  pleasures  which 
cannot  be  enjoyed  by  the  ignorant.  The  absorbing  in- 
terest which  the  Mathematician  and  the  Philologist  fre- 
quently feel  in  their  studies,  is  a  striking  instance  of  the 
direct  pleasure  derivable  from  knowledge,  even  in  its 
most  abstract  form :  and  although  these  are  studies  in 
which  the  majority  of  mankind  cannot  be  expected  to 
feel  a  deep  interest,  yet  the  case  is  otherwise  with  vari- 
ous departments  of  knowledge.  If  we  except  the  few 
who  are  insane,  or  only  a  little  above  idiocy,  all  mankind 
delight  in  observing  the  beauties  and  wonders  of  nature. 
Many,  also,  feel  much  interested  in  witnessing  great  and 
stirring  historical  scenes :  and  although  these  may  be 
placed  beyond  the  reach  of  observation,  yet  the  pages  of 
History  disclose  them,  in  countless  numbers.  To  persons 
who  prefer  tracing  the  lives  of  distinguished  or  remark- 
able individuals,  Biography  offers  an  extensive  field  of 
similar  enjoyment. 

The  sources  of  these  pleasures  are  as  varied  as  the 
subjects  of  thought.  For,  besides  the  mathematical  and 
physical  sciences,  Ethnography,  History  and  Biography, 
there  is  the  wide  field  of  the  mental  sciences,  which  will 
ever  possess  the  strongest  attractions  for  all  who  desire 
to  penetrate  to  the  causes  of  observed  phenomena,  and 
trace  the  ultimate  laws  by  which  they  are  regulated. 

There  are  not  only  different  fields  of  enjoyment,  but 
also  various  subdivisions  of  the  same  field,  so  that  every 
individual's  precise  taste  may  be  gratified.  He  who  dis- 


SEC.  3.]         ADVANTAGES  OP  KNOWLEDGE.  19 

relishes  the  stormy  scenes  of  politics  or  war,  may  trace 
the  progress  of  religion,  science  and  literature,  or  study 
the  history  of  manners  and  social  life ;  he  who  delights 
in  contemplating  external  nature,  as  it  is  presented  to 
our  immediate  view,  can  study  Geography,  while  those 
who  prefer  to  analyse  its  materials,  may  study  Chemistry 
and  Geology:  one  who  desires  to  contemplate  vast  ob- 
jects, may  have  recourse  to  Astronomy ;  and  he  who 
would  inspect  the  minute  works  of  the  Creator,  can  study 
Physiology  and  Entomology,  while  those  who  wish  to 
examine  the  inventions  of  man,  are  furnished  with  an  ex- 
tensive field,  in  the  various  processes  and  results  of  Art. 

Nor  do  those  pleasures,  by  any  means,  end  with  the 
first  acquisition  :  for  they  may  be  renewed  whenever  we 
choose  to  recollect  the  objects  which  first  excited  them ; 
and  although  much  may  have  been  forgotten,  yet  the 
most  striking  and  impressive  parts  will  generally  be  re- 
membered, on  account  of  the  strong  attention  and  feel- 
ing which  they  originally  excited. 

4.  Knowledge  is  necessary  to  prevent  mankind  from 
addicting  themselves  to  evil  practices  which  mar  their 
happiness.  The  desire  of  enjoyment  exists  constantly  in 
every  mind :  and  hence  those  who  are  unacquainted  with 
the  pleasures  which  accompany  knowledge,  and  are  nev- 
er obtained  by  the  ignorant,  devote  themselves  to  the 
only  enjoyments  of  which  they  know.  From  this  source 
have  sprung  the  various  forms  of  sensuality,  with  the 
fearful  evils  which  they  have  inflicted  on  the  human  race, 
and  many  pastimes  which  exert  a  most  disastrous  influ- 
ence on  their  devotees.  Yet  such  enjoyments  will  ever 
be  eagerly  sought  by  those  who  have  found  nothing  bet- 
ter ;  and  this  can  be  done  only  by  acquainting  ourselves 
with  the  mighty  and  wonderful  works  of  God,  the  treas- 
ures of  Science  and  Art,  the  records  of  History  and  Bi- 
ography, and  the  numerous  objects  which  exercise  our 
sympathies,  and  require  our  active  efforts,  throughout  the 
world. 

Those  various  subjects  are  much  more  than  sufficient 
to  occupy  all  the  time  that  can  be  spared  from  important 
duties ;  and  they  furnish  a  field  of  harmless  and  exalted 
enjoyment  which  the  longest  life  and  most  diligent  study 
can  never  exhaust.  When  we  learn  to  enjoy  such  pleas- 
ures, and  at  the  same  time  know  the  great  evils  that  re- 
sult from  those  practices,  it  will  not  be  a  difficult  matter 


20  INTRODUCTION. 

to  discontinue  them  forever.  For  such  knowledge  dis- 
closes to  us  those  objects  which  excite  our  strongest  and 
purest  emotions,  as  well  as  the  worthlessness  of  those 
practices  as  means  of  happiness,  and  the  numerous  priva- 
tions and  sufferings  which  they  entail  on  their  votaries. 

5.  Knowledge  is  requisite  to  our  physical  welfare  and 
safety.  The  value  of  the  useful  arts,  for  these  purposes, 
is  obvious ;  and  although  the  dependence  of  many  of 
them  on  sciences  apparently  of  no  practical  application 
is  not  so  easily  seen,  it  is  not  the  less  real.  A  knowledge 
of  the  properties  of  abstract  quantity  seems,  at  first  sight, 
to  be  utterly  removed  from  the  business  of  life ;  yet  it 
forms  the  foundations  of  many  important  arts,  and  of  the 
science  of  Astronomy,  whose  aid  is  requisite  to  enable 
the  navigator  to  cross  the  ocean  in  safety,  and  convey 
the  superabundant  food  of  one  hemisphere  to  the  famish- 
ing millions  of  another.  So  the  discoveries  of  the  Chem- 
ist, the  Botanist,  and  the  Physiologist,  improve  the  art  of 
Agriculture,  and  promote  the  preservation  and  restora- 
tion of  health. 

Without  the  aids  furnished  by  superior  intelligence, 
man  would  be  in  a  worse  condition  than  the  lower  ani- 
mals :  for  in  childhood  he  is  helpless,  and  he  comes  to 
maturity  very  slowly ;  he  is  destitute  of  natural  clothing 
or  means  of  defence ;  he  is  much  inferior  to  many  of  the 
brutes  in  bodily  strength ;  and  the  spontaneous  produc- 
tions of  the  earth  do  not  suffice  for  his  sustenance.  Hence 
not  only  his  welfare,  but  his  very  existence  is  wholly  de- 
pendent on  his  superior  knowledge. 

"We  are  incessantly  surrounded  by  agencies,  and  tempt- 
ed to  yield  to  certain  allurements,  which  tend  to  injure 
health  and  produce  premature  death ;  and,  in  order  to 
escape  the  bad  effects  of  exposure  to  their  influence,  we 
require  a  knowledge  of  their  nature,  and  of  the  proper 
means  of  guarding  against  them,  which  is  often  unattain- 
able without  extensive  and  careful  investigation. 

It  is  only  by  the  aid  of  knowledge  that  men  will  in- 
dustriously follow  proper  methods  for  supplying  their 
physical  wants,  or  secure  the  fruits  of  their  labor,  and 
make  a  right  use  of  them  after  they  have  been  acquired. 
But  a  knowledge  of  God,  of  man,  and  of  external  nature, 
produces  industry,  justice,  abundance  of  everything  req- 
uisite to  supply  our  physical  wants,  temperance  in  the 
use  of  them,  a  proper  degree  of  care  against  external 
dangers,  and  a  general  observance  of  the  laws  of  health. 


SEC.  3.]         ADVANTAGES  OF  KNOWLEDGE.  21 

The  physical  welfare  of  a  community  also  requires 
many  conveniences  which  can  be  furnished  only  where  a 
dense  population  admits  of  a  great  division  of  labor, 
while  such  a  population  cannot  exist  happily  without  an 
extensive  and  accurate  knowledge  of  the  art  of  cultiva- 
ting the  soil,  and  of  the  proper  modes  of  regulating  the 
distribution  of  its  productions.  For  otherwise  the  lar- 
ger portion  of  the  community  will  inevitably  suffer  from 
want,  and  drag  on  a  wretched  existence,  surrounded  by 
the  strongest  temptations  to  vice. 

6.  Knowledge  is  necessary  to  secure  common  morality, 
and  render  ordinary  business  safe  and  agreeable.     We 
are  beset  by  various  inducements  to  act  immorally  to- 
wards others,  so  strong  that  we  shall  frequently  yield  to 
their  influence,  unless  we  are  fortified  against  it  by  a 
knowledge  of  the  motives  to  virtue,  and  the  sure  conse- 
quences of  vice.    Hence  serious  offences  of  this  kind  will 
always  abound  among  a  people  ignorant  on  the  subject 
of  their  duties,  and  an  ignorant  community  is  addicted 
to  several  vices,  against  which  he  who  deals  with  its 
members  must  incessantly  guard,  in  order  to  avoid  seri- 
ous pecuniary  loss,  and  other  great  evils  incident  to  such 
intercourse. 

The  prevalent  vices  of  nations  and  individuals  widely 
vary ;  and  as  every  one  is  apt  to  look  at  the  bright  side 
of  his  own  and  the  dark  side  of  his  neighbours'  character, 
he  readily  concludes  that  he  is,  upon  the  whole,  tolerably 
virtuous,  while  an  impartial  observer  might  find  that  both 
are  equally  immoral,  their  respective  failings  differing  only 
in  kind,  and  not  in  degree. 

The  general  connection  between  ignorance  and  crime 
is  shown  by  the  fact  that,  in  every  intelligent  communi- 
ty, the  majority  of  criminals  belongs  to  the  small  fraction 
of  society  which  is  illiterate,  and  that  the  slaves  of  vice 
are  uniformly  found  to  be  grossly  ignorant  regarding  the 
nature  and  sanctions  of  morality.  They  frequently  know 
something  on  these  subjects ;  but  their  views  of  them 
are  radically  erroneous.  Knowledge  removes  such  evils, 
by  imparting  proper  affections  towards  others  and  steady 
moral  principles. 

7.  Knoidedge  guards  its  against  the  numberless  impo- 
sitions that  are  practised  on  the  ignorant,  by  the  design- 
ing and  unprincipled.     Impositions  of  this  kind  often 
enable  men  to  obtain  others'  property  without  giving  a 


22  INTKODUCTION. 

fair  equivalent  in  return,  while  they  escape  the  penalties 
attached  to  robbery  or  theft ;  and  hence  the  extreme 
prevalence  of  such  frauds,  which  have  produced  much 
evil.  Ignorance  and  its  ordinary  concomitant,  credulity, 
may  be  said  to  be  the  capital  on  which  the  various  class- 
es of  deceivers  and  impostors  have  traded  in  all  ages : 
and  they  disappear  only  where  men  have  become  too  en- 
lightened to  be  deceived ;  for  the  same  bad  training  that 
makes  one  man  a  credulous  dupe,  will  make  a  person  of 
a  different  disposition  a  cheat. 

Frauds  and  impositions  have  been  extremely  common, 
on  account  of  the  wide  field  presented  by  ignorant  cre- 
dulity, and  because  there  are  as  many  temptations  to  such 
deceptions  as  there  are  evil  passions  or  depraved  appe- 
tites. Yet  a  knowledge  of  the  devices  and  falsehoods  of 
the  unprincipled,  the  criterions  of  truths,  and  the  laws  of 
nature,  would  banish  all  these  evils  from  society.  A 
very  ordinary  knowledge  of  Physiology  and  Pathology, 
for  example,  would  enable  us  to  detect  the  impositions 
of  a  quack,  who  professed  to  cure  all  diseases  with  a  sin- 
gle nostrum :  a  knowledge  of  the  character  of  God  and 
the  nature  and  condition  of  man,  would  banish  religious 
deceptions :  the  young  and  unwary  would  escape  the 
snare,  if  they  knew  the  character  and  objects  of  the  in- 
snarer :  and  men  would  very  rarely  believe  any  false  as- 
sertions, if  they  were  well  acquainted  with  the  requisites 
of  credible  testimony  and  the  sources  of  error. 

8.  Knowledge  is  requisite  to  free  the  mind  from  su- 
perstition. History  abounds  with  instances  of  the  dis- 
mal effects  which  have  flowed  from  this  source.  Under 
its  influence,  the  most  civilized  and  enlightened  nations 
of  antiquity  became  addicted  to  the  vilest  and  most  cruel 
practices,  even  to  murdering  their  own  offspring  and  im- 
molating themselves,  in  order  to  appease  the  supposed 
wrath  or  procure  the  favor  of  deities  that  existed  only 
in  their  own  benighted  imaginations.  And  even  where 
those  more  revolting  superstitions  passed  away,  the  pu- 
erilities and  disgusting  practices  of  succeeding  times  de- 
based the  mind,  and  shut  out  the  light  of  truth.  Super- 
stition not  only  produces  particular  evils,  but  also  substi- 
tutes its  own  worthless  forms  and  pernicious  doctrines 
in  the  place  of  truth,  and  generally  surrounds  the  minds 
of  its  victims  with  a  web  of  prejudices  and  errors,  which 
renders  them  satisfied  with  fatal  ignorance. 


SEC.  3.]         ADVANTAGES  OF  KNOWLEDGE.  23 

Wherever  true  religion  is  absent,  superstition  inevita- 
bly appears :  for  the  phenomena  of  nature  lead  us  irre- 
sistibly to  a  superior  power,  of  which  our  conceptions 
must  be  either  accurate  or  the  reverse ;  and  the  belief  in 
a  future  state  is  too  deeply  rooted  in  our  nature  to  be 
eradicated  by  any  sophistry,  however  subtle.  Hence 
some  form  of  superstitious  belief  and  practice  exists 
wherever  people's  views  of  the  superior  power  and  a  fu- 
ture state  are  radically  erroneous.  But  a  knowledge  of 
the  character  and  government  of  the  only  true  God,  of 
the  relation  in  which  we  stand  to  him,  and  of  the  laws 
of  nature,  banishes  superstitious  opinions  and  practices, 
as  the  effects  disappear  with  their  cause. 

9.  The  acquisition  of  knowledge  is  requisite  to  dis- 
cipline  the  intellect ,  and  Jit  it  for  a  proper  performance 
of  duty.  It  is  a  matter  of  daily  observation  that  the 
characters  of  persons  and  the  amount  of  good  which  they 
effect,  depend  much  more  on  their  training  than  on  the 
native  force  of  their  understandings.  Many  men  of  or- 
dinary abilities  become,  by  proper  mental  discipline  and 
instruction,  happy  and  useful  members  of  society,  while 
others,  of  great  native  talents,  have  often,  for  want  of 
these  advantages,  spent  miserable  lives,  and  were  justly 
regarded  as  public  pests. 

The  intellectual,  like  the  corporal,  faculties  require  suit- 
able exercise,  in  order  to  the  proper  performance  of  those 
functions  for  which  they  were  conferred,  while  such  ex- 
ercise is  found  only  in  a  proper  course  of  study  and  ob- 
servation, for  the  attainment  of  knowledge.  As  a  man 
cannot  be  made  a  good  sailor  by  following  the  plough, 
so  a  person  cannot  be  fitted  for  properly  discharging  his 
various  duties,  unless  his  intellect  has  been  exercised  on 
those  very  subjects  with  which  he  is  to  be  conversant  in 
after  life.  In  order  to  discharge  our  duties  towards  God 
or  man,  we  must  possess  a  correct  knowledge  of  the  di- 
vine character ;  and  this  is  unattainable  unless  our  minds 
are  properly  trained  in  investigating  his  works  and 
words. 

Ignorance  inevitably  leads  to  innumerable  pernicious 
errors,  both  of  opinion  and  practice.  We  must  think  and 
act ;  and  unless  we  are  guided  by  knowledge,  we  shall 
both  think  and  act  in  such  a  manner  as  not  only  to  miss 
the  great  object  of  all  our  pursuits,  but  also  to  inflict 
many  serious  and  permanent  evils  upon  others.  On  many 


24  INTRODUCTION. 

subjects,  ignorance  is  evidently  so  dangerous  and  disre- 
putable that  men  are  not  satisfied  without  possessing 
something  which  will  pass  for  knowledge,  while  they 
may  be,  in  reality,  so  ignorant  that  they  readily  adopt 
for  truth  errors  recommended  by  their  own  prejudices 
or  the  authority  of  persons  in  whom  they  confide,  with- 
out ever  mistrusting  that  there  is  anything  wrong. 

Besides  religion,  we  meet  with  opinions  on  many  other 
subjects,  firmly  believed  by  the  unenlightened  portion 
of  mankind,  which  men  acquainted  with  those  subjects 
know  to  be  totally  false.  Such  are,  the  opinion  that  some 
persons  are  lucky  and  others  unlucky,  independently  of 
character,  conduct  and  circumstances ;  that,  by  means  of 
certain  simple  manipulations,  a  person  can  be  made  to  see 
better  without  than  with  the  use  of  his  eyes ;  that  men 
can  perform  miracles  by  means  of  satanic  agency ;  that 
certain  diseases  can  be  cured  by  rubbing  the  affected 
part  to  a  corpse — and  so  forth. 

Thus  ignorance  not  only  excludes  knowledge,  but  sub- 
stitutes in  its  place  a  spurious  belief,  much  worse  than 
none. 

Some  have  maintained  that  ignorance  is  favorable  to 
happiness,  and  knowledge  dangerous  and  pernicious. 
But  happy  ignorance  exists  only  in  the  realms  of  pure 
imagination.  We  have  the  highest  authority  for  assert- 
ing that,  in  ancient  times,  the  people  perished  for  want 
of  knowledge  ;*  and  the  need  of  it  is  equally  great  in  ev- 
ery age.  We  are  also  told  that  ignorance  is  an  evil,  and 
knowledge  a  great  good,f  statements  which  are  confirm- 
ed by  all  the  annals  of  our  race.  Certain  kinds  of  knowl- 
edge are  liable  to  be  abused :  but  this  cannot  occur  with 
a  man  who  knows  his  duties,  and  is  at  the  same  time  in- 
fluenced by  those  emotions  and  moral  principles  which 
uniformly  accompany  an  accurate  and  extensive  acquaint- 
ance with  the  most  important  subjects  of  human  investi- 
gation :  and  hence  the  evils  attributed  to  knowledge  are, 
in  reality,  the  effects  of  ignorance. 

From  the  preceding  survey,  we  see  that  the  proper  ac- 
quisition of  knowledge  furnishes  three  distinct  advant- 
ages :  1.  It  supplies  the  information  requisite  to  right 
conduct,  and  to  avoid  pernicious  courses.  2.  It  trains 

*  Prophecies  of  Hosea,  chapter  iv.,  verse  6. 

f  Proverbs  of  Solomon,  chapter  xviii.,  verse  15  ;  chapter  xix.,  verse 
27  ;  and  Ecclcsiastcs,  chapter  vii.,  verse  12. 


SEC.  3.]         ADVANTAGES  OP  KNOWLEDGE.  25 

the  faculties,  and  renders  them  able  to  perform  their  func- 
tions properly.  3.  It  aifords  various  direct  enjoyments, 
which  can  be  repeated  indefinitely. 

The  degree  of  knowledge  requisite  for  the  purposes 
mentioned,  is  not  attainable  except  by  means  of  investi- 
gations conducted  in  accordance  with  the  principles  of 
Logic ;  and  these  require  to  be  studied,  in  order  to  be 
known.  This  is  proved  by  the  grave  errors  and  mis- 
takes committed  by  many  investigators,  and  the  igno- 
rance or  erroneous  opinions  of  a  great  majority  of  man- 
kind, on  all  the  most  important  subjects,  from  the  earli- 
est times  to  this  day. 

B 


PART  I, 


OF  THE  ULTIMATE  SOURCES  AND  ELEMENTS  OF 

KNOWLEDGE,  AND  THE  PRIMARY  PROCESSES 

BY  WHICH  IT  IS  ACQUIRED  AND 

RETAINED. 


CHAPTER  I. 

A  GENERAL  VIEW    OF   THE   LIMITS,  DIVISIONS,  AND   IMME- 
DIATE  SOURCES    OF   KNOWLEDGE. 

§  1.  NECESSARY  LIMITS  AND  PRINCIPAL-DIVISIONS  or  KNOWLEDGE. 
— (1)  Knowledge  limited  to  Intuitions,  Comprehensions,  and  Infer- 
ences.— Peculiarities  of  these  several  classes. — Boundaries  of  the 
Knowable  and  of  the  Known. — Distinction  between  Knowledge  and 
Belief. — (2)  Knowledge  either  Mediate  or  Immediate. — Definition 
of  Cognition,  Consciousness,  and  Discernment. — Truths  known  by 
the  latter. — (3)  Knowledge  consists  of  Necessary,  Contingent,  and 
Hypothetical  Cognitions. — Branches  belonging  to  each. — Common 
properties  of  all. 

1.  EVERYTHING  which  we  can  know,  must  belong  to 
one  or  other  of  the  three  following  classes  of  truths. 

(1)  Those  which  are  self-evident,  or  which  we  know 
must  be  such,  and  cannot  possibly  be  otherwise,  inde- 
pendently of  anything  made  known  to  us  by  our  senses. 
Such  are,  the  existence  and  essential  nature  of  time  and, 
space — that  contradictories  cannot  co-exist,  and  that  a 
thing  is  equivalent  to  itself.     These  we  term  intuitions, 
and  the  faculty  or  power  by  which  we  know  them  In- 
tuition. 

(2)  Truths  not  necessarily  such,  but  made  known  to 
us  directly  by  Comprehension,  the  faculty  by  which  we 
directly  know  truths  which  -are  not  self-evident.     Thus, 
when  we  behold  the  sky,  we  certainly  see  a  blue  expanse ; 
when  we  smell  a  rose,  we  feel  a  particular  odor;  when 
we  have  succeeded  in  effecting  a  difficult  object  which 
we  deem  important,  we  feel  a  pleasant  emotion ;    and 
when  we  think  of  a  tree  which  we  have  often  seen,  we 
have  an  idea  of  its  appearance.     Truths  of  this  class  we 
term  comprehensions. 

(3)  Inferential  truths,  or  those  which  are  necessarily 
implied  in  intuitions,  comprehensions,  or  suppositions, 
and  which  we  term  inferences.     By  necessary  implica- 
tion is  meant,  such  a  connection  that  the  inferences  must 
be  true,  and  cannot  possibly  be  false,  "if  the  things  from 
which  they  are  inferred  are  true; 

These  three  classes  of  truths  include  everything  that 


oC          LlJiITS    AND    SGLKCES    OF    KNOWLEDGE.     [ClIAP.  I. 

can  possibly  be  known:  for  it  is  evident  that  we  cannot 
possibly  know  a  thing  if  it  is  not  knowable  by  any  of  the 
faculties  by  which  we  obtain  direct  knowledge,  nor  sus- 
ceptible of  being  found  to  be  implied  in  anything  which 
we  can  either  know  or  suppose.  Hence — (1)  any  inves- 
tigation which  lies  beyond  these  limits  is  fruitless,  such 
as  an  inquiry  into  the  origin  of  life,  or  the  atomical  struc- 
ture of  matter — (2)  everything  within  these  limits  is 
knowable — and  (3)  no  statement  is  entitled  to  be  classed 
with  known  truths,  till 'it  has  been  clearly  ascertained  to 
be  an  intuition,  a  comprehension,  or  an  inference. 

It  is  also  evident  that  everything  which  we  actually 
know,  must  be  knoAvn  directly  or  indirectly,  and  that 
whatever  is  known  directly  must  be  so  because  it  is 
known  to  be  either  self-evident  or  presented  by  some 
faculty  that  we  possess  of  directly  knowing  truths  which 
are  not  of  the  former  class.  It  is  equally  evident  that  a 
truth  can  be  known  indirectly  only  in  consequence  of  its 
being  found  to  be  necessarily  connected  with  something 
that  is  known  directly.  Hence  the  intuitions,  compre- 
hensions and  inferences  which  a  person  knows  to  be 
such,  form  all  his  actual  knowledge.  Intuitions  and  in- 
ferences not  known  to  be  such,  things  once  comprehend- 
ed but  afterwards  totally  forgotten,  and  things  never 
comprehended,  evidently  form  no  part  of  our  act  rial 
knowledge. 

Knowledge  can  be  only  of  truths :  for  although  we 
may  believe  error  we  cannot  know  it,  since  this  implies 
that  it  is  either  a  truth  known  directly  to  be  such,  or 
that  it  is  sustained  by  conclusive  proof,  which  error  can- 
not possibly  be.  Knowledge  also  implies  belief;  and 
therefore  a  truth  which  a  man  rejects,  or  does  not  be- 
lieve, is  not  known  to  him,  however  well  it  may  be  known 
to  others,  and  even  if  he  formerly  believed  it  himself,  on 
good  grounds. 

2.  We  distinguish  -unknown  truths  from  the  known  by 
terming  the  latter  cognitions,  which  may  be  defined — 
truths  known  to  be  such.  Intuitions  and  comprehen- 
sions may  be  termed  immediate  or  direct  knowledge,  as 
we  know  them  directly,  without  the  intervention  of  any 
proof  or  process.  •  The  two  faculties  of  Intuition  and 
Comprehension  may  be  designated  by  the  common  term 
Consciousness  or  ^Discernment  •  and  truths  known  by 
it  may  be  called  discernments.  These  arc  accompanied 


SEC.  1.]   NECESSARY  LIMITS,  &c.,  OF  KNOWLEDGE.     31 

with  a  direct  knowledge  of  their  certainty,  so  that  they 
require  no  proof;  and  they  may  be  said  to  be  discerned. 
Inferences,  being  made  known  only  by  intermediate 
proofs  and  processes,  may  be  termed  mediate  or  indirect 
knowledge. 

Consciousness  includes  the  knowledge  which  we  neces- 
sarily have  of  the  reality  of  all  our  present  thoughts  and 
their  immediate  objects,  or  those  things  of  which  we 
think.  It  is  self-evident  that  we  cannot  think  without 
knowing  that  we  think,  and  that  we  cannot  know  unless 
there  is  something  that  we  know.  When  we  see,  for  ex- 
ample, there  must  be  something  that  we  see,  and  we 
necessarily  know  that  we  see.  So  when  we  feel,  we  nec- 
essarily know  that  we  feel,  and  that  there  is  something 
which  we  do  feel. 

3.  There  is  no  necessity  for  our  possessing  compre- 
hending faculties,  such  as  we  actually  possess,  nor  for  the 
existence  of  the  things  comprehended.  Thus  some  men 
cannot  see,  and  the  things  which  we  see  might  have  had 
no  existence.  Comprehensions  may,  therefore,  be  ternied 
contingent  truths :  and  those  which  are  necessarily  im- 
plied in  them  are  properly  classed  under  the  same  term. 
As  these  depend  on  contingencies,  they  are  not  necessa- 
rily true ;  for  a  necessary  connection  between  two  things 
does  not  imply  the  existence  of  either,  but  only  that  if 
one  exists,  the  other  must  exist. 

Another  class  of  cognitions  is,  that  which  expresses 
certain  properties  or  relations  of  things  merely  supposed 
or  assumed,  and  having  possibly  no  actual  existence. 
These  may  be  called  hypothetical  truths.  Such  are,  the 
properties  of  a  machine  which  has  yet  no  actual  exist- 
ence, but  is  merely  planned  by  the  inventor,  and  conse- 
quences which  have  been  proved  to  follow  a  certain 
course  of  conduct,  which  is  only  supposed,  and  has  not 
been  actually  adopted. 

As  inferences  from  intuitions  are  necessary  truths  a.? 
much  as  the  original  intuitions,  both  classes  fall  under 
that  class  of  cognitions.  Hence  necessary,  contingent 
and  hypothetical  cognitions  include  all  human  knowl- 
edge. The  first  class  comprises  what  must  be ;  the  sec- 
ond, what  actually  was,  is,  or  will  be,  though  not  neces- 
sarily ;  and  the  third,  what  will  be,  if  certain  things  are 
assumed  or  pre-supposed. 

These  three  classes  of  truths  do  not  differ  in  respect 


32       LIMITS  AND  SOURCES  OF  KNOWLEDGE.    [CHAP.  I. 

to  certainty :  all  are  equally  certain,  where  they  agree 
with  the  proper  criterions,  and  we  are  liable  to  err  in  re- 
gard to  each.  Statements  have  been  believed  to  be  self- 
evident  which  are  untrue,  and  fallacious  mathematical 
demonstrations  are  by  no  means  unknown,  while,  at  the 
same  time,  contingent  and  hypothetical  cognitions  may 
be  established  conclusively,  although  this  is  frequently 
more  difficult  than  the  demonstration  of  a  mathematical 
theorem. 

§  2.    OF  THE  VARIOUS  FACULTIES  BY  WHICH  KNOWLEDGE  IS  ACQUIRED 

AND  RETAINED. — Definition  of  Faculty. — Nature  of  Apprehension. 
— Knowledge  acquired  through  Apprehensions. — Reasoning. — Na- 
ture of  Remembrance. — On  what  dependent. — Similitudes,  Ideas, 
Phantasms,  and  Prototypes.  —  Comprehensions.  —  Knowledge  de- 
pendent on  Remembrance. — Nature  of  Emotions,  and  what  we 
know  directly  by  them. — Nature  and  general  laws  of  Attention. — 
Nature  of  Abstraction,  and  of  Conception. — Notions  and  Imagina- 
tions.— Nature  of  Generalization. — Six  things  which  necessarily 
exist  in  all  Thinking. — Frequent  Errors. 

I?y  a  Faculty  is  understood  a  power,  capacity  or  sus- 
ceptibility of  thinking,  feeling  or  acting.  Hence  what- 
ever we  do,  we  must  have  a  faculty  of  doing,  and  what- 
ever we  feel,  we  must  have  a  faculty  of  feeling.  We 
cannot,  for  instance,  see  without  the  power  of  seeing ; 
we  cannot  reason  without  the  power  of  reasoning ;  and 
we  cannot  feel,  unless  we  are  susceptible  of  feeling. 

That  we  see  colors,  hear  sounds,  and  smell  odors,  are 
sure  truths,  whatever  difference  of  opinion  may  prevail 
regarding  the  origin  of  such  cognitions.  The  faculties 
by  which  we  thus  obtain  immediate  knowledge,  through 
the  influence  of  things  external  to  the  mind,  are  termed 
apprehending  faculties  or  Apprehension,  and  the  cogni- 
tions obtained  apprehensions.  They  are  all  properly 
classed  together  here,  since  they  resemble  each  other  in 
depending  on  some  impression  made  on  a  nerve,  by 
means  of  which  a  corresponding  impression  is  made  on 
the  mind. 

The  knowledge  thus  obtained  consists  of  sensations, 
or  the  pleasant  and  painful  feelings  which  we  experience, 
and  perceptions,  or  that  of  which  we  are  conscious,  be- 
sides what  we  feel.  Thus,  when  we  vjew  a  green  field, 
the  green  expanse  which  we  behold  is  quite  distinct  from 
the  pleasing  or  painful  feelings  which  accompany  this 
perception. 


SEC.  2.]  OF  THE  FACULTIES.  33 

As  we  know  intuitively  that  certain  truths  necessarily 
imply  others,  we  learn  the  existence  and  observable  prop- 
erties of  material  and  living  beings  by  applying  the  fac- 
ulty of  Intuition  to  our  apprehensions.  Those  truths  are 
not  apprehended  directly;  but  they  are  implied  in  our 
apprehensions,  and  learned  by 'means  of  reasoning  or 
drawing  necessary  inferences,  the  faculty  of  Intuition, 
when  thus  applied,  being  termed  Reason.  Thus,  when 
we  view  a  tree,  the  eye  perceives  only  extended  colors : 
but,  by  observing  all  the  phenomena,  and  drawing  the 
necessary  inferences,  we  find  that  there  is  a  solid  body 
without  us,  of  a  particular  form,  size,  and  color. 

In  drawing  inferences,  we  are  not  confined  to  what  we 
have  personally  apprehended :  for,  by  means  of  testi- 
mony, we  learn  the  apprehensions  of  others;  and  we  can 
draw  inferences  from  these  as  we  do  from  things  pri- 
marily apprehended  by  ourselves.  Certain  sounds  and 
visible  characters  are  found  to  denote  certain  things,  by 
means  of  which  we  learn  the  thoughts  of  others.  We 
determine  what  those  sounds  and  characters  imply,  by 
the  proper  application  of  our  faculties,  as  in  other  inves- 
tigations. 

While  tracing  inferences,  we  are  frequently  obliged 
to  reason  about  things  not  apprehended  at  the  time. 
Thus,  in  proving  conclusions,  it  is  generally  necessary  to 
refer  to  things  which  are  not  present  to  our  senses,  such 
as  things  previously  seen,  heard  or  proved.  This  is  done 
by  means  of  Remembrance,  the  faculty  by  which  we  know 
our  former  thoughts. 

If  we  carefully  consider  the  phenomena  of  Remem- 
brance, we  shall  find  that  it  is  not  a  simple  faculty,  but 
that  it  depends  on  two  things.  If  we  view  a  tree,  and 
then  close  our  eyes,  we  may  still  discern  a  faint  and  fleet- 
ing likeness  of  it ;  and  we  find  that  the  same  is  true  of 
all  our  apprehensions :  and  so  all  other  thoughts,  also, 
have  their  likenesses,  after  the  originals  have  disappear- 
ed. These  likenesses  I  term  similitudes.  They  may  be 
subdivided  into  two  classes  —  ideas,  or  similitudes  of 
apprehensions  —  and  phantasms,  or  similitudes  of  other 
thoughts,  besides  apprehensions.  The  original  of  a  si- 
militude I  term  its  prototype.  Trains  of  similitudes  pass 
spontaneously  through  the  mind,  according  to  certain 
laws ;  and  the  simple  faculty  of  discerning  them  I  call 
Memory.  Apprehensions,  similitudes  and  all  other  things 
B  2 


34       LIMITS  AND  SOURCES  OF  KNOWLEDGE.    [CHAP.  I. 

directly  discerned,  except  intuitions,  are  included  under 
the  general  term  comprehensions. 

When  we  consider  the  phenomena  of  similitudes,  Intu- 
ition leads  us  to  the  conclusion  that  they  all  had  their 
prototypes  :  for  all  other  suppositions  involve  an  absurd- 
ity, as  we  shall  see  hereafter.  Thus,  by  means  of  Mem- 
ory and  Intuition,  we  can  know  and  reason  about  the  past 
as  if  it  were  the  present.  The  last  alone  is  known  im- 
mediately, in  respect  of  all  contingent  truths,  whose  past 
and  future  are  known  only  by  their  being  necessarily 
connected  with  something  present. 

On  comparing  the  peculiarities  of  the  various  objects 
of  thoughts,  we  find  a  large  class  which,  unlike  appre- 
hensions, is  immediately  independent  of  anything  beyond 
the  mind.  These  consist  of  similitudes  and  of  feelings 
which  differ  widely  from  those  of  Apprehension,  although 
remotely  dependent  on  them.  These  are  generally  term- 
ed emotions /  and  they  resemble  apprehensions  in  being 
known  solely  by  Consciousness.  We  know  the  existence 
and  character  of  our  feelings  solely  from  experiencing 
them,  and  neither  by 'intuition,  by  reasoning,  nor  by  the 
testimony  of  others,  although  we  may  investigate  their 
origin,  laws  and  component  elements,  as  in  the  case  of 
other  thoughts.  They  also  directly  teach  us  nothing  but 
their  own  existence  and  nature.  We  feel  nothing  but 
our  feelings  :  we  cannot  feel  the  truth  of  any  assertion. 
Thus  we  cannot  fe'el  that  the  sky  is  blue,  that  Alexander 
the  Great  died  at  Babylon,  that  things  equal  to  the  same 
thing  are  equal  to  each  other,  nor  that  the  three  angles 
of  a  triangle  are  equal  to  two  right  angles. 

We  attend  to  that  of  which  we  think ;  and  the  power 
of  doing  so  is  termed  attention.  This  is  of  two  kinds. 
Spontaneous  attention  is  that  which  is  produced  by  some 
present  feeling,  without  desire  or  effort ;  and  it  is  gener- 
ally proportional  to  the  strength  and  vividness  of  the 
feeling ;  but  where  these  become  intense,  they  nearly  ab- 
sorb the  attention,  or  make  us  overlook  other  present 
objects  of  thought.  Voluntary  attention  is  that  which 
is  produced  by  a  desire  or  effort  of  the  Will,  directing  it 
to  something  which  we  deem  of  consequence ;  and  it  is 
generally  proportional  to  the  importance  of  the  subject, 
according  to  our  belief;  but  where  we  consider  this  very 
great,  the  subject  may  nearly  absorb  the  attention,  like 
strong  feelings.  The  actual  degree  of  attention  is  fre- 


SEC.  2.]  OF  THE  FACULTIES.  05 

quently  the  result  of  the  two  kinds  operating  simultane- 
ously, and  proportional  to  their  united  amount :  but  it 
often  depends  on  one  alone. 

Attention  is  evidently  not  a  distinct  power  of  the 
mind,  but  merely  a  general  name,  to  denote  the  exercise 
of  our  faculties  with  reference  to  particular  objects  of 
thought :  and  it  is  usually  exerted  with  reference  to  sev- 
eral objects  at  the  same  instant.  During  our  waking 
state,  we  generally  attend  simultaneously  to  our  appre- 
hensions and  ideas.  Thus,  when  wre  walk  with  a  friend, 
we  attend  to  the  organs  of  motion  and  speech,  hear  his 
conversation,  observe  various  objects  around  us,  and  at- 
tend to  the  subjects  of  conversation,  so  that  we  collect 
the  sense  of  what  he  says,  and  form  our  own  replies. 
But  it  is  observable  that  the  force  of  attention  diminish- 
es as  the  number  of  objects  simultaneously  considered 
increases. 

When  we  discern  different  things  at  the  same  time,  we 
have  the  power  of  concentrating  the  attention  on  some 
and  overlooking  the  rest.  Thus,  while  viewing  a  tree,  we 
may  ponfine  our  attention  to  the  trunk,  the  branches,  the 
leaves,  or  the  blossoms ;  and,  with  respect  to  the  latter, 
we  may  consider  their  form,  their  odor,  their  color,  or 
their  position  and  arrangement.  This  faculty  is  termed 
Abstraction,  which  may  be  defined  as  that  by  which  we 
fix  the  attention  on  particular  objects  of  thought,  and 
withdraw  it  from  others,  at  pleasure,  or  as  long  as  the 
object  is  present.  In  the  case  of  apprehensions,  the  phe- 
nomena of  course  vanish  when  their  causes  are  with- 
drawn ;  but,  with  regard  to  similitudes,  we  may  retain 
and  consider  them  till  mere  weariness  or  exhaustion  in- 
duces us  to  turn  to  something  else. 

Abstraction  is  spontaneous  where  it  results  simply 
from  the  pleasure  or  pain  of  a  particular  feeling,  and  vol- 
untary where  we  voluntarily  limit  the  attention,  for  some 
purpose,  which  is  discovered  by  the  aid  of  Reason. 
Hence  the  exercise  of  voluntary  abstraction  is  dependent 
on  the  latter  faculty.  Yet  it  is  a  distinct  power,  which 
is  requisite  in  order  to  discover  the  peculiar  and  general 
properties  of  the  various  objects  of  human  research. 

Besides  observing  the  phenomena  of  Comprehension, 
find  drawing  inferences  from  them,  we  can  modifyHthe 
(simple  elements,  and  combine  them  into  a  new  whole, 
different  from  any  which  we  ever  comprehended.  Thus, 


36      LIMITS  AND  SOUKCES  OP  KNOWLEDGE.    [CHAP.  I. 

we  can  think  of  a  small  horse  from  having  seen  a  large 
one,  or  of  a  circle  being  elongated  into  an  ellipse,  or  of 
the  half  of  it,  without  the  rest,  or  of  a  green  horse  with 
an  ox's  head.  The  combination  may  be  either  of  the  com- 
prehensions or  of  the  modifications  previously  thought  of, 
or  of  the  two  blended,  as  in  the  case  of  the  last  instance 
just  mentioned,  in  which  case  there  is  a  double  exercise 
of  the  same  faculty.  We  may  afterwards  modify  and  re- 
combine  the  combination,  and  so  on,  without  any  definite 
limit,  except  what  arises  from  the  greater  difficulty  of 
the  new  combinations,  on  account  of  their  greater  com- 
plexity. 

This  faculty  we  term  Conception,  and  the  thing  thought 
of,  a  conception.  If  this  be  of  something  not  described 
nor  known,  we  term  it  an  imagination :  if  it  be  of  some- 
thing described  or  represented  to  us  by  others,  we  term 
it  a  notion.  Thus,  an  inventor  imagines  something  new, 
and  a  person  forms  a  notion  of  a  plant  or  an  animal  from 
a  description.  Conception,  when  employed  in  imagin- 
ing, is  termed  Imagination :  but  it  is  essentially  the 
same  throughout,  both  in  its  nature  and  its  processes. 

When  we  compare  several  objects,  we  often  perceive 
that,  although  they  greatly  differ  in  some  respects,  yet 
they  have  certain  properties  in  common.  Thus,  the  sky 
and  the  ocean  are  both  blue;  flint,  iron,  and  diamond  are 
all  hard;  water,  oil  of  turpentine,  and  alcohol  are  all 
liquid;  and  oxygen,  hydrogen,  and  nitrogen  are  all  gas- 
eous bodies ;  the  planet  Venus  revolves  round  the  8un, 
and  so  does  Mars,  &c.  When  we  thus  note  or  ascertain 
a  common  property  of  several  things,  we  are  said  to  gen- 
eralize /  and  the  knowledge  obtained  is  rendered  perma- 
nent and  available  by  means  of  general  terms,  or  words 
that  express  the  common  property,  wherever  it  exists. 
In  this  process  there  is  no  new  faculty  employed,  but 
only  several  of  those  already  described. 

In  all  thinking  there  necessarily  exist  six  distinct 
things — (1)  that  which  thinks,  or  the  mind — (2)  the  fac- 
ulty by  which  it  thinks — (3)  the  thought,  or  some  act  or 
exercise  of  the  faculty — (4)  the  object  of  the  act,  or  that 
which  is  discerned,  known,  believed  or  supposed — (5)  a 
knowledge  of  the  reality  both  of  the  act  and  of  its  imme- 
diate object  —  and  (6)  something  which  originates  or 
causes  the  act,  which  may  be  either  in  the  mind  or  with- 
out. Thus,  when  we  see,  there  are — (1)  the  mind,  that 


SEC.  3.]  OF  PROPOSITIONS.  37 

sees — (2)  the  faculty  of  vision — (3)  an  exercise  of  this 
faculty — (4)  the  thing  seen,  or  the  colors — (5)  a  knowl- 
edge that  we  think  and  see  these  colors — and,  (6)  the 
cause  of  our  seeing  them,  which  is,  the  action  of  rays  of 
light  on  the  retina. 

Various  errors  have  arisen  from  confounding  several 
of  those  things  with  each  other,  which  happens  the  more 
readily  because  they  are  designated  by  the  same  term. 
A  common  instance  is,  confounding  apprehensions  with 
those  qualities  of  substances  which  cause  them,  as  when 
it  is  said  "  I  feel  the  heat  of  the  fire."  The  confusion 
becomes  evident  from  the  difficulty  which  is  generally  ex- 
perienced in  distinguishing  the  perception  of  color  from 
the  objective  reality  which  causes  it.  We  do  not  readi- 
ly believe  that  there  can  be  nothing  either  in  or  on  the 
colored  substance  which  in  the  least  resembles  its  color, 
any  more  than  there  can  be  anything  in  a  bell  resembling 
its  sounds.  A  similar,  but  much  less  common,  error  is, 
confounding  thought  with  the  thinker.  The  former  is 
only  an  act  of  the  latter,  arid  totally  different  from  its 
essence  or  substance,  of  which  it  cannot  possibly  form  a 
part. 

§  3.  OF  Puo POSITIONS. — Definition  of  Propositions. — Subject  and 
Predicate. — Expression  of  a  Proposition. — Converse,  contrary,  and 
contradictory  of  a  Proposition. — Identical  Propositions. — Import- 
ant property  of  these. — Simple,  Alternative  or  Disjunctive,  and 
Complex  or  Compound  Propositions. — Absolute  and  Conditional 
or  Hypothetical  Propositions. — Affirmative  and  Negative  Proposi- 
tions.— Universal,  General,  Particular  or  Indefinite,  and  Individual 
or  Singulaf  Propositions. — Frequent  ambiguities. — Various  forms 
of  Propositions. — Caution.  — Combinations. 

Everything  affirmed  or  denied  is  expressed  by  &  prop- 
osition, which  is,  an  assertion  of  a  truth,  assumption,  sup- 
position, belief  or  opinion  :  and  it  is  either  expressed  in 
words  or  simply  declared  by  the  mind.  It  may  refer  to 
the  past,  the  present,  or  the  future,  or  to  any  two  of  them, 
or  to  all  time. 

Every  proposition  necessarily  consists  of  at  least  two 
parts,  the  one  relating  to  the  thing  of  which  something 
is  said,  or  the  subject,  and  the  other,  to  wrhat  is  said  of  it, 
which  is  termed  the  predicate.  Thus,  in  the  proposition 
"just  men  abhor  deception"  the  first  two  words  are  the 
subject,  and  -the  latter,  the  predicate.  These  are  essen- 
tial parts  of  every  proposition,  since,  in  every  assertion, 


38       LIMITS  AND  SOURCES  OF  KNOWLEDGE.    [CHAP.  I. 

there  must  be  something  of  which  we  assert,  and  some- 
thing which  is  asserted  regarding  it.  The  subject  and 
predicate  may  each  consist  of  a  single  term,  as  "  John 
sleeps,"  or  of  *a  long  clause,  as  "  every  one  who  desires 
the  welfare  of  his  country,  will  cheerfully  submit  to  pri- 
vations, for  the  public  good,  during  times  of  general  dis- 
tress ;"  or  each  part  may  consist  of  several  connected 
clauses,  as  "the  true  patriot,  and  the  wise  and  upright 
statesman,  will  not  be  turned  from  the  path  of  duty,  ei- 
ther by  the  threats  of  the  powerful  or  the  clamor  of  the 
multitude."  (2) 

The  proper  expression  of  a  proposition  requires  at  least 
two  words,  one  denoting  the  thing  spoken  of,  and  the 
other,  what  is  said  of  it.  The  common  idiom  of  a  lan- 
guage may,  indeed,  require  only  one  word,  as  in  the  Lat- 
in expression" pluit,  (which  is  equivalent  to  "  it  rains  :") 
but,  in  all  such  cases,  some  second  word  is  understood. 
Thus  the  preceding  verb  has  some  nominative  under- 
stood, such  as  Jupiter,  or  Deus  (God).  So  the  English 
expressions  yes  and  no  are  only  abbreviations  for  a  re- 
sponsive repetition  of  the  terms  of  the  question. 

The  converse  of  a  proposition  is  one  in  which  the  sub- 
ject is  asserted  of  the  thing  predicated,  so  that  subject 
and  predicate  change  places.  Thus — "those  who  abhor 
deception  are  just  men,"  is  the  converse  of  the  first  ex- 
ample given  above.  The  contrary  of  a  proposition  is 
one  which  predicates  the  contrary  attribute  of  the  same 
subject.  Thus — "John  is  iceak"  is  the  contrary  of  "«7o/m 
is  strong"  By  contrary  attributes  are  meant  those  which 
are  most  unlike,  of  the  same  class,  as  good  and  bad,  wise 
and  foolish,  hard  and  soft,  high  and  low,  black  and  white, 
light  and  heavy.  The  contradictory  of  a  proposition  is 
one  which  denies  of  the  subject  the  attribute  which  the 
former  asserted.  Thus  —  "John  is  not  strong"  is  the 
contradictory  of  "John  is  strong." 

An  identical  proposition  is  one  which  predicates  the 
subject  of  itself,  or  whose  subject  and  predicate  are  iden- 
tical, as  "  a  man  is  a  man" — "  azote  is  another  name  for 
nitrogen" — "Philip  was  the  father  of  Alexander" — "Lon- 
don is  the  capital  of  the  British  Empire."  To  this  class 
of  propositions  belong  all  verbal  definitions,  or  those 
which  explain  the  signification  of  terms,  provided  that 
they  are  accurate — and  it  is  an  evident  property  of  the 
whole  class  that,  if  the  original  proposition  is  true,  so  is 
the  converse. 


SEC.  3.]  OP  PROPOSITIONS.  39 

A  simple  proposition  is  one  which  attributes  a  single 
property  to  a  single  thing,  as  "  John  died."  One  which 
attributes  one  or  other  of  several  properties  to  a  sub- 
ject, is  termed  alternative  or  disjunctive,  as  "  John  is  ei- 
ther in  London  or  in  Paris  or  in  New  York."  A  com- 
plex or  compound  proposition  attributes  various  proper- 
ties to  the  same  or  to  different  things,  as  "  man  is  mor- 
tal, and  yet  frequently  forgets  his  mortality" — "John 
died  yesterday,  and  James  died  to-day."  Propositions 
of  this  kind  consist  of  several  simple  propositions  united, 
into  which  they  may  be  resolved.  On  the  other  hand, 
where  the  different  things  contained  in  a  compound  prop- 
osition form  one  whole,  and  the  same  thing  is  attributed 
to  every  one  of  them,  the  compound  proposition  may 
be  expressed  simply.  Thus,  the  compound  proposition 
"John  is  a  descendant  of  Adam;  Mary  is  a  descendant 
of  Adam,  etc."  is  tantamount  to  "  All  mankind  are  de- 
scendants of  Adam." 

An  absolute  or  unconditional  proposition  affirms  the 
predicate  absolutely,  without  any  condition,  as  "All  men 
are  mortal."  A  conditional  or  hypothetical  proposition 
predicates  only  upon  some  condition  or  supposition,  as 
"If  report  be  true,  all  men  are  mortal"  —  "Although  he 
should  do  that,  he  would  gain  nothing  by  it." 

An  affirmative  proposition  asserts  the  predicate  of  the 
subject,  as  "John  is  dead."  A  negative  proposition  de- 
nies it,  as  "  John  is  not  dead" — "  No  man  is  mortal." 

A  universal  proposition  predicates  of  all  the  individ- 
uals of  a  class  or  all  the  parts  of  a  whole,  as  "  All  men 
are  mortal" — "No  matter  is  unextended."  A  general 
proposition  predicates  of  most  of  a  class  or  whole,  as 
"  Most  men  are  rational"' — "  Carbonic  acid  is  generally 
gaseous."  A  particular  or  indefinite  proposition  affirms 
or  denies  of  a  small  or  indefinite  part,  as  "Some  men  are 
wise."  A  singular  or  individual  proposition  predicates 
of  a  single  individual  or  part  of  a  whole,  as  "John  thinks" 
— "  This  piece  of  wood  is  brittle." 

The  classes  of  propositions  defined  in  the  preceding 
paragraph  are  frequently  expressed  in  such  a  manner  as 
to  render  the  extent  of  the  subject  ambiguous  or  doubt- 
ful. Thus,  in  the  proposition  "  Man  is  mortal,"  the  sub- 
ject may  mean  either  "every  man"  or  only  "Most  men." 
So,  "Men  say  so" — may  mean  "All"  or  "Most"  or  only 
"  Some  men."  Such  ambiguities  have  been  a  frequent 
occasion  of  error. 


40      .LIMITS  AND  SOURCES  OF  KNOWLEDGE.   [CHAP.  L 

Propositions  m.iy  frequently  be  varied  in  the  form  of 
expression,  so  as  to  bring  them  under  a  different  class, 
without  in  the  least  changing  their  signification.  Thus, 
the  conditional  proposition  "  If  report  be  true,  all  men 
are  rational,"  is  equivalent  to  the  absolute  proposition 
"  It  is  reported  that  all  men  are  rational,"  or,  "  The  ra- 
tionality of  all  men  is  reported."  So  the  affirmative  prop- 
osition "  All  men  are  mortal"  is  tantamount  to  the  nega- 
tive proposition  "  No  man  is  immortal ;"  and  "  John  is 
not  dead"  is  equivalent  to  "  John  is  alive."  As  the  nega- 
tive of  an  attribute  is  tantamount  to  the  affirmative  of  its 
contradictory,  every  negative  proposition  may  be  con- 
verted into  an  equivalent  affirmative.  Hence  it  appears 
that,  in  examining  propositions,  we  should  regard  their 
real  signification  or  import,  rather  than  their  form. 

The  several  kinds  of  propositions  may  be  combined 
with  each  other  indefinitely.  Thus,  the  proposition  "  If 
John  did  that,  he  is  either  a  knave  or  a  fool,"  combines 
the  conditional  and  alternative  forms.  So  we  may  com- 
bine the  conditional  with  an  affirmative  or  negative,  sim- 
ple or  compotmd1  universal  or  particular,  and  so  forth. 

§  4.  OF  PROBABILITY. — Definition  of  Probability. — (1)  Probabilities 
founded  on  previous  experience  regarding  the  concomitance  of  cer- 
tain properties. — What  these  imply. — When  they  become  certain- 
ties.— Principle  of  Reasoning. — (2)  Probabilities  founded  on  what 
we  know  has  happened  in  cases  apparently  similar. — Principle  of 
Reasoning. — Why  we  often  err. — Connection  between  Agencies 
and  their  Results. — (3)  Probabilities  based  solely  on  what  must 
happen. — Distinction  between  these  and  the  preceding  classes. — 
Source  of  frequent  error,  and  mode  of  avoiding  it. — (4)  Probabili- 
ties founded  on  the  known  connection  between  Causes  and  Effects. 
— Use  of  Experience.  — Common  error. — (/>)  Probabilities  based  on 
actual  investigation  of  proof. — Distinction  between  Probability  and 
Certainty.  Principles  of  Reasoning  in  all  cases  of  Probability. — 
Influence  of  individual  Experience. — Uses  of  Probability. — Cir- 
cumstances in  which  it  exists,  and  to  what  generally  proportional. 
— Resultant  Probabilities. — Means  of  ascertaining  their  value. 

A  probability  is,  a  proposition  implying  facts  which 
tend  to  prove,  but  which  do  not  absolutely  prove,  that  it 
is  a  truth.  Probabilities  are  of  various  kinds,  the  most 
common  of  which  are  included  under  one  or  other  of  the 
five  following  classes. 

1:  In  comparing  two  things,  we  frequently  observe 
that  they  possess  many  obvious  properties  in  common ; 
and  although  there  is  no  proof  that  they  possess  unob- 


SEC.  4.]  OP  PROBABILITY.  41 

served  properties  in  common,  yet  experience  informs  us 
that  this  has  been  found  to  hold  true,  in  similar  instan- 
ces ;  and  this  we  indicate  by  saying  that  such  improbably 
the  case.  Here  the  probability  implies,  not  only  that  a 
proposition  may  be  true,  but  that  it  has  actually  been 
found  true,  in  similar  cases ;  and  the  probability  is  great- 
er or  less,  according  as  the  cases  in  which  the  unobserved 
attributes  were  afterwards  found  to  be  common,  are  more 
or  less  numerous,  or  as  the  resemblance  is  more  or  less 
extensive. 

Of  this  kind  is  the  probability  that  a  certain  effect 
will  follow  from  an  agency  similar  to  one  whose  effects 
are  known,  that  an  effect  has  been  produced  by  a  cause 
known  to  have  produced  similar  effects,  and  that  two  or 
more  similar  phenomena  have  similar  causes,  antecedents, 
concomitants  or  effects.  Other  cases  are,  that  the  testi- 
mony of  a  person  of  doubtful  veracity  or  a  stranger,  re- 
garding some  unknown  subject,  is  true,  that  a  man  will 
continue  to  act  as  he  has  hitherto  done,  in  apparently 
similar  circumstances,  that  a  certain  phenomenon  has 
.been  preceded  by  its  usual  antecedent,  or  the  reverse, 
and  that  a  newly  discovered  species  will  be  found  simi- 
lar, in  unobserved  attributes,  to  known  species  to  which 
it  bears  a  general  resemblance. 

This  class  of  probabilities  is  based  on  the  self  evident 
principle  that  where  the  determining  conditions  or  agen- 
cies are  the  same,  the  results  will  be  the  same.  When- 
ever we  ascertain  that  the  conditions  or  agencies  are  act- 
ually the  same,  in  two  or  more  cases,  the  results  must  be 
the  same,  and  probability  gives  place  to  certainty,  as  the 
former  exists  only  where  we  know  but  of  a  partial  simi- 
larity of  the  determining  conditions. 

2.  Results  are  found  to  vary,  in  cases  apparently  simi- 
lar, while  the  previous  variations  are  known.  Thus,  if  a 
person  has  succeeded  in  effecting  a  certain  result,  by  the 
same  apparent  means,  in  seven  cases  out  of  ten,  we  say 
the  probability,  or  chance  of  his  succeeding,  in  the  next 
attempt,  is  seven  tenths,  and  of  his  failing,  three  tenths, 
the  cases  being  all  alike,  so  far  as  is  known.  We  reason 
on  the  self-evident  principle  that  results  must  follow  as 
they  have  done,  in  the  same  circumstances.  But  there 
is  frequently  no  means  of  ascertaining  that  the  several 
cases  are,  in  reality,  perfectly  alike ;  and  hence  the  future 
results  often  turn  out  differently  from  what  the  probabil- 


42       LIMITS  AND  SOURCES  OF  KNOWLEDGE.   [CHAP.  I. 

ity  indicated.  Such  probabilities  are  evidently  propor- 
tional to  the  ratio  which  the  favorable  cases  bear  to  the 
whole. 

Whatever  affects  the  agencies  concerned  in  producing 
results,  will  affect  these  in  a  corresponding  degree. 
Thus,  greater  attention  to  the  laws  of  health,  in  a  com- 
munity, increases  the  probability  that  a  person  of  a  cer- 
tain age,  taken  at  random,  will  live  so  many  years ;  and 
greater  temperance  among  seamen  will  lessen  the  chances 
that  a  ship  will  be  lost  at  sea.  The  probability  varies, 
in  such  cases,  as  the  agencies  which  determine  the  re- 
sults vary. 

3.  One  or  other  of  several  results  must  happen,  and 
we  know  no  reason  why  one  should  happen  more  than 
another.     Thus,  as  a  certain  day  must  be  fair  or  foul,  we 
say  it  is  an  even  chance  that  it  will  be  fair.     Here  the 
probability  varies  inversely  according  to  the  number  of 
possible  results,  being  greater  as  these  are  fewer,  and 
conversely.      These   differ  widely  from   the   preceding 
kinds  of  probability :  for  here  our  expectations  are  based 
solely  on  what  must  happen,  independently  of  any  knowl- 
edge as  to  what  has  happened,  and,  unless  experience 
prove   the    contrary,  there   may  be  unknown  agencies 
which  will  interfere  with  the  expected  results.     Thus,  if 
a  certain  time  of  the  year  is  generally  fair,  there  is  more 
than  an  even  chance  that  the  day  will  be  fair,  and  con- 
versely.    It  is,  therefore,  very  unsafe  to  act  on  the  as- 
sumption that  certain  results  will  follow,  where  we  are 
ignorant  of  what  has  happened,  in  circumstances  similar 
in  reality,  and  not  merely  in  appearance. 

4.  A  certain  change  must  have  resulted  from  one  or 
other  of  several  causes,  or  a  cause  must  have  produced 
one  or  other  of  several  results,  and  we  have  no  reason  to 
decide  in  favor  of  one  agency  or  result  more  than  anoth- 
er.    Thus,  a  disease  must  have  arisen  from  some  viola- 
tion of  the  laws  of  health,  or  from  some  original  unsound- 
ness  of  constitution,  or  from  both  combined ;  and,  there- 
fore, we  might  say,  where  we  know  nothing  regarding 
the  person  affected,  the  chances  are  one  third,  or  one  to 
three,  that  it  has  proceeded  solely  from  an  unsound  con- 
stitution.   The  degree  of  probability  varies  with  the  num- 
ber of  causes  or  results.     But  experience  is  here  pecu- 
liarly requisite,  since  we  cannot  generally  decide,  with 
certainty,  as  to  the  number  of  causes  which  may  have  op- 


SEC.  4.]  OP  PKOBABILITY.  43 

crated,  and  we  are  liable  to  substitute  mere  suppositions 
instead  of  the  real  agencies  concerned  in  producing  the 
results.  Many  baseless  scientific  theories  have  origin- 
ated in  this  manner.  Experience  frequently  alters  ab- 
stract probabilities  of  this  kind,  so  that  the  actual  proba- 
bility is  the  result  of  a  combination  of  various  elements. 
Thus,  in.  the  case  just  mentioned,  when  we  come  to  know 
the  extreme  frequency  of  violation  of  the  laws  of  health, 
and  the  comparatively  rare  cases  in  which  original  con- 
stitutional defects  are  the  sole  cause  of  disease,  we  shall 
find  that  the  chance  of  such  a  defect  being  the  sole  cause 
of  a  disease,  instead  of  being  one  to  three,  is  not  one  to 
three  hundred. 

With  regard  to  the  results  which  a  certain  agent  may 
be  expected  to  produce,  we  generally  reason  more  on 
our  previous  experience  than  on  necessity;  and  we  are 
apt  to  assume  a  degree  of  similarity,  in  two  cases,  which 
does  not  actually  exist,  as  when  it  is  assumed  that  a  med- 
icine will  produce  one  or  other  of  two  results  on  a  pa- 
tient, because  it  has  done  so  in  other  cases  apparently 
similar,  although  the  former  may  differ  in  several  import- 
ant peculiarities. 

5.  The  proofs  which  support  a  certain  proposition  have 
been  examined,  and  we  infer  that  it  is  true ;  but  the  ex- 
amination has  not  been  so  close  or  thorough  as  to  ex- 
clude the  possibility  of  mistake.  Here  the  probability 
varies  with  the  degree  of  care  employed  in  the  examina- 
tion. If  it  has  been  conducted  by  others,  and  not  by 
ourselves,  the  degree  of  probability  will  vary  with  their 
character,  being  higher  or  lower,  according  as  they  are 
careful  investigators  and  faithful  relators  or  the  reverse. 

When  the  subject  has  been  examined  in  such  a  man- 
ner as  to  leave  no  possible  room  for  any  error,  the  con- 
clusion is  certain,  and  not  merely  probable.  But  we  can 
never  safely  assume  this  regarding  the  conclusions  of  oth- 
ers, unless  we  have  properly  tested  them,  as  we  cannot 
know  that  their  examination  is  of  that  character.  They 
furnish  only  probabilities,  which  vary  with  the  character 
and  circumstances  of  our  informants. 

In  this  .class  of  cases,  we  reason  on  the  self-evident 
principle  that  the  probability  of  a  proposition  varies  ac- 
cording to  the  nature  of  the  proof  by  which  it  is  sus- 
tained. • 

From  its  nature,  no  degree  of  probability  can  amount 


44       LIMITS  AND  SOURCES  OF  KNOWLEDGE.   [CHAP.  I. 

to  a  certainty ;  nor  does  the  one  pass  by  insensible  gra- 
dations into  the  other.  When  a  proposition  has  been 
found  to  be  certainly  true,  this  immediately  places  it  in 
a  class  widely  removed  from  probabilities.  We  must 
beware,  however,  of  adopting  any  probability  as  a  cog- 
nition until  we  have  obtained  conclusive  proof. (3) 

In  every  case  of  probability  we  reason  upon  .self-evi- 
dent principles,  as  in  cases  where  we  arrive  at  certainty ; 
but,  in  the  former,  we  reason  from  evidences  which  are 
incomplete  or  inconclusive,  and  consequently  the  results 
partake  of  the  nature  of  their  sources,  whereas,  in  the 
latter,  the  foundations  are  known  truths,  and,  therefore, 
if  our  arguments  or  proofs  are  legitimate,  our  conclusions 
are  absolutely  true. 

Men  are  apt  to  base  their  views  of  probability  mainly 
on  their  individual  views  and  experience,  while  they 
either  reject  or  do  not  know  the  experience  or  knowl- 
edge of  others :  and  hence  the  same  proposition  often 
appears  very  probable  to  one  and  extremely  improbable 
to  another.  Thus,  Herodotus  disbelieved  the  statement 
of  the  Phoenician  mariners,  who  had  sailed  round  Africa, 
that,  during  part  of  their  voyage,  the  sun  rose  on  the 
right  hand  when  they  faced  its  position  at  noon,  whereas 
a  person  who  possessed  a  more  extensive  knowledge  of 
Astronomy  would  consider  such  a  statement  highly  prob- 
able, if  not  a  matter  of  course. 

Although  probability  never  amounts  to  knowledge, 
yet  it  is  often  of  great  consequence,  both  in  scientific  in- 
vestigations and  in  the  ordinary  business  of  life.  In  the 
former  case  it  acts  as  a  guide  and  stimulant,  and  many 
truths  would  never  have  been  discovered,  had  there  been 
no  previous  indications  pointing  to  a  certain  conclusion. 
It  guides  us  in  establishing  the  proposition  in  question, 
by  pointing  out  what  is  wanting,  in  order  to  that  end ; 
and  it  stimulates  to  investigation  by  showing  that  more 
or  less  of  the  task  is  already  accomplished,  and  thus  prom- 
ising important  results  for  comparatively  little  toil.  It  is 
also  of  great  value  in  many  of  the  ordinary  affairs  of  life ; 
for  it  enables  us  to  determine  the  most  eligible  course, 
where  certainty  is  unattainable. 

Probability  exists  only  where  we  have  partial  knowl- 
edge, and  are  at  the  same  time  ignorant  on  some  points 
which  we  require  to  know,  in  order  to  possess  certainty. 
Where  we  are  totally  ignorant,  we  know  of  no  probabil- 


SEC.  5.]    GENERAL  CRITERION  OF  TRUTH,  &c.  45 

ity ;  and  where  our  knowledge  is  sufficiently  extensive, 
the  probability  gives  place  to  certainty.  The  degree  of 
probability  is  generally  proportional  to  our  knowledge 
of  what  is  requisite  to  be  known,  in  order  to  arrive  at 
certainty. 

The  probability  of  the  truth  of  a  certain  proposition 
is  often  the  resultant  of  several  probabilities  combined, 
every  one  diminishing  or  increasing  the  preceding,  ac- 
cording as  it  is  discordant  or  accordant.  Thus,  the  prob- 
ability that  a  certain  testimony  is  true,  may  be  the  re- 
sultant of  the  probability  that  the  witness  knows  the 
truth,  and  that  he  asserts  what  he  believes.  The  prob- 
ability of  his  knowing  the  truth,  again,  may  be  the  re- 
sultant of  several  remoter  probabilities,  such  as  his  means 
of  ascertaining  the  truth,  the  use  he  has  made  of  them, 
the  tenacity  of  his  memory,  and  the  relation  between  his 
statements  and  those  of  others  who  possessed  the  means 
of  forming  a  right  judgment  on  the  subject. 

The  resultant  of  several  accordant  and  independent 
probabilities  is  generally  proportional  to  their  total 
amount ;  and  where  there  are  discordant  probabilities, 
the  resultant  generally  varies  with  the  difference  between 
the  amount  of  the  former  and  that  of  the  latter  kind. 

The  resultant  of  connected  probabilities,  or  probabil- 
ities of  probabilities,  generally  varies  as  the  product  of 
the  factors  expressing  the  value  of  each.  Thus,  if  it  is  an 
even  chance  that  a  witness  correctly  knows  what  he  re- 
lates, and  a  similar  chance  that  he  reports  correctly  ivhat 
he  knows,  the  probability  that  his  statement  is  true,  is 
only  as  one  to  four.  In  such  cases  eveiy  new  probabil- 
ity introduced  may  diminish  the  resultant. 

§  5.  GENERAL  CRITERION  or  TRUTH,  AND  IMMEDIATE  SOURCE  OP 
ERROR. — Apprehensions  real,  and  why. — Only  possible  sources  of 
Error. — How  these  may  be  avoided. — Distinctions  between  Appre- 
hensions and  Ideas. — All  other  Comprehensions  like  the  former. — 
How  we  ascei-tain  whether  a  proposition  is  self-evident. — Requisites 
to  the  validity  of  inferences. — How  these  are  distinguishable  from 
Intuitions. — How  inattention  occasions  error. — Expression  of  the 
general  criterion  of  Truth,  and  the  immediate  source  of  Error. — 
How  erroneous  Belief  may  be  avoided. — Its  uniform  concomitant. 
Belief  includes  Knowledge  and  Opinion. 

Not  only  are  we  directly  conscious  of  our  apprehen- 
sions, but  we  know  intuitively  that  it  is  impossible  for 
any  being  to  believe  that  he  thus  apprehends  when,  in 


46       LIMITS  AND  SOURCES  OF  KNOWLEDGE.    [CHAP.  I. 

reality,  be  does  not.  Thus,  when  I  view  the  clear  sky, 
I  know  immediately  that  I  perceive  a  blue  expanse ;  and 
when  I  feel  pain,  I  have  a  direct  and  unerring  knowledge 
of  the  reality  of  ray  sensation.  This  holds  equally  true 
of  every  sensation  and  perception. 

It  is  self-evident  that  no  apprehension  can  exist  with- 
out attention.  Thus,  when  the  attention  is  completely 
absorbed  by  other  thoughts,  a  person  exposed  to  a  freez- 
ing temperature  can  have  no  sensation  of  cold,  and  if  a 
clock  should  strike  near  him,  he  cannot  hear  it.  It  is 
common  to  have  apprehensions  which  are  immediately 
forgotten,  because  they  excite  very  little  attention :  but 
it  is  impossible  for  us  to  apprehend  without  any  atten- 
tion whatever  to  the  thing  apprehended ;  otherwise  we 
should  be  conscious  of  that  of  which  we  were  not  con- 
scious, or  think  what  we  did  not  think. 

The  only  possible  sources  of  error,  on  this  point,  are, 
mistaking  one  apprehension  for  another,  or  for  a  simili- 
tude :  and  it  requires  only  a  moderate  degree  of  atten- 
tion to  avoid  such  errors,  since  the  various  kinds  of  ap- 
prehensions are  palpably  different  from  each  other,  and 
similitudes  are  much  fainter  and  under  the  control  of  the 
Will.  Thus,  there  is  no  danger  of  mistaking  a  sound  for 
a  color,  or  even  the  smell  of  a  rose  for  that  of  tobacco. 
So  it  is  very  easy  to  distinguish  the  mere  idea  of  the 
Moon  from  actually  seeing  it :  for  not  only  are  our  organs 
of  vision  very  differently  affected  in  the  two  cases,  but  it 
requires  no  effort  of  the  Will  to  continue  the  apprehen- 
sion, whereas  the  mere  idea  speedily  gives  place  to  some 
other  thought,  unless  we  retain  it  by  a  conscious  effort 
of  the  Will.  On  the  other  hand,  we  may  discern  the  idea 
at  pleasure,  whereas  the  apprehension  is  dependent  on  the 
presence  of  its  cause,  and  ceases  when  that  disappears. 

The  reality  of  other  comprehensions  admits  of  as  little 
rational  doubt  as  that  of  apprehensions.  Thus,  when  I 
discern  the  idea  of  a  tree,  I  am  as  conscious  of  the  real- 
ity of  the  discernment  as  if  I  viewed  the  tree.  Atten- 
tion is  here  even  more  requisite  than  in  the  former  case, 
as  there  is  no  external  object  to  excite  the  comprehen- 
sion. 

We  are  liable  to  mistake  an  apprehension  for  its  idea ; 
but  the  peculiarities  which  distinguish  the  former  are  so 
obvious  that  it  requires  only  a  little  attention  to  avoid  this 
error.  The  same  remark  applies  to  the  distinctions  be- 


SEC.  5.]    GENERAL  CIUTERION  OF  TRUTH,  &c.  47 

tween  the  other  kinds  of  comprehensions.  Thus,  an  idea 
is  distinguished  from  a  conception  by  the  former  being 
spontaneous,  while  the  latter  is  the  result  of  a  voluntary 
effort,  and  less  vivid  ;  and  it  is  distinguished  from  a 
phantasm  by  our  recollecting  the  latter's  origin,  and  its 
exhibiting  the  peculiarities  of  its  prototype.  We  avoid 
error  here  precisely  as  in  the  case  of  apprehensions  and 
ideas. 

Hence  we  may  see  that  attention  will  enable  us  to 
avoid  errors  in  regard  to  all  comprehensions,  and  that 
these  must  arise  from  inattention,  as  in  the  case  of  appre- 
hensions. 

In  order  to  determine  whether  a  proposition  is  an  in- 
tuition or  self-evident  truth,  we  have  only  to  consider  it 
with  attention  :  for  the  very  nature  of  an  intuition  is, 
that  the  attentive  mind  discerns  its  necessary  truth,  and 
its  falsity  to  be  an  impossibility.  We  may  first  consider 
whether  it  is  discerned  to  be  self-evidently  and  neces- 
sarily true ;  and  if  we  have  any  hesitation,  it  may  be  re- 
moved by  considering  whether  its  contradictory,  or  the 
proposition  denying  its  truth,  is  possible :  for  if  we  have 
the  evidence  of  consciousness  either  way,  that  suffices. 
A  proposition  which  must  necessarily  be  true,  and  one 
which  cannot  possibly  be  false,  are  evidently  both  enti- 
tled to  equal  and  perfect  credence,  and  free  from  the  pos- 
sibility of  a  rational  doubt  regarding  their  truth. 

Our  comprehensions  and  intuitions  are  often  intuitive- 
ly known  to  imply  cognitions  entirely  different  from 
themselves ;  these  may  be  known,  in  the  same  way,  to 
imply  others,  and  so  on,  without  any  definite  limit.  The 
existence  of  A,  for  example,  may  necessarily  imply  that 
of  B,  which  may  prove  that  of  C,  and  so  on.  The  num- 
ber of  these  intermediate  cognitions  is  a  matter  of  no  es- 
sential importance.  All  that  is  necessary,  in  order  to  es- 
tablish the  ti'uth  of  the  last  inference,  is,  that  the  original 
proposition  be  true,  and  that  there  be  a  self-evident  con- 
nection between  every  cognition  and  the  proposition 
which  immediately  follows.  This  can  be  ascertained  by 
attentively  considering  whether  one  proposition  neces- 
sarily implies  that  which  is  immediately  founded  on  it, 
or  deduced  from  it ;  for  if  it  does,  the  connection  becomes 
self-evident  upon  an  attentive  consideration  and  compari- 
son of  both. 

Owing  to  the  extreme  rapidity  of  thought,  we  are  lia- 


48       LIMITS  AND  SOURCES  OF  KNOWLEDGE.   [CHAP.  I. 

ble  to  mistake  inferences  for  intuitions  or  comprehen- 
sions, since  we  may  overlook  the  processes  by  which  we 
arrived  at  them :  but  a  proper  degree  of  attention  will 
always  show  their  true  character ;  for  the  distinction  be- 
tween discernments  and  inferences  is  as  easily  discover- 
ed as  that  between  intuitions  and  apprehensions. 

Inattention  occasions  error  by  its  leading  us  to  over- 
look differences,  or  to  draw  immaterial  distinctions,  or  by 
concealing  something  from  view  altogether.  There  is  no 
other  possible  way  in  which  we  can  be  led  into  error : 
for  we  can  mistake  one  thing  for  another  only  by  over- 
looking differences  or  drawing  unimportant  or  irrelevant 
distinctions  ;  and  if  everything  which  concerns  the  sub- 
ject is  clearly  before  the  attentive  mind,  there  can  be  no 
false  or  unwarrantable  inferences. 

Thus  it  appears  that  the  general  criterion  of  truth  is, 
the  evidence  of  attentive  Consciousness ,  either  direct  or 
indirect.  The  former  tests  comprehensions  and  intui- 
tions, and  the  latter,  inferences.  It  also  appears  that  in- 
attention is  the  sole  immediate  source  of  erroneous  opin- 
ions, wliich  all  spring  from  our  not  being  sufficiently  at- 
tentive to  those  things  which  must  be  carefully  consid- 
ered, in  order  to  attain  to  truth. 

That  we  often  believe  what  is  false,  does  not  in  the 
least  prove  that  we  can  never  certainly  know  whether 
any  proposition  is  true.  Wherever  our  belief  is  errone- 
ous, there  must  have  been  a  want  of  attentive  considera- 
tion of  one  or  more  of  the  circumstances  necessary  to 
form  a  correct  opinion :  for  it  is  obvious  that,  if  the  orig- 
inal assumption  cannot  be  false,  and  that  it  necessarily 
implies  a  certain  inference,  the  latter  must  be  true. 
There  is  a  certain  number  of  steps  in  every  process,  ev- 
ery one  of  which  we  can  consider  with  the  greatest  at- 
tention ;  and  hence  we  can  know  whether  we  have  given 
the  proper  degree  of  attention  to  every  point  which 
ought  to  be  considered. 

Where  there  is  any  room  for  doubt  or  uncertainty,  as 
to  whether  we  have  sufficiently  attended  to  every  point, 
we  are  not  warranted  in  assuming  the  proposition  in 
question  as  established.  But  wherever  we  know  that 
this  has  been  done,  the  proposition  cannot  be  false.  In 
every  case  of  erroneous  belief,  we  may  discover  a  want 
of  due  attention  on  one  or  more  points.  Thus,  in  dream- 
ing, insanity  and  delirium,  similitudes  are  taken  for  pro- 


SEC.  1.]          NATURE,  &c.,  OF  REASONING.  49 

totypes,  because  characteristic  peculiarities  are  overlook- 
ed. In  such  cases,  indeed,  there  is  hardly  an  attentive 
consideration  of  anything,  but  merely  a  train  of  ideas  or 
apprehensions  passing  through  the  mind,  accompanied 
with  those  thoughts  which  they  immediately  excite.  So, 
when  we  mistake  a  false  inference  for  an  intuition,  we 
cannot  have  carefully  considered  whether  the  proposition 
is  really  intuitive. 

Belief  includes  all  that  we  believe,  or  take  to  be  true, 
whether  true  or  false.  It  may  be  subdivided  into  'knowl- 
edge and  opinion.  Knowledge  is,  belief  based  on  atten- 
tive consideration  and  the  evidence  of  consciousness  at 
every  step,  so  that  there  is  no  room  for  error,  and  no 
reasonable  ground  for  doubt  or  disbelief.  Opinion  in- 
cludes all  other  belief,  whether  correct  or  not. 


CHAPTER  II. 

OF     REASONING. 

§  1.  NATURE,  GENERAL  PRINCIPLE,  AND  EXPRESSION  OF  REASONING. 
— Two  kinds  of  Knowledge  obtained  by  means  of  Intuition. — Na- 
ture and  definition  of  Reasoning. — Identity  of  the  process,  in  every 
case. — Its  importance. — General  principle  of  Reasoning. — Extent 
of  its  application. — Definitions  of  Syllogism  and  its  parts. — Differ- 
ent modes  of  expressing  Syllogisms. — Best  mode. — Part  frequently 
suppressed. — When  it  ought  to  be  expressed. — Reason  for  a  thing. 

THE  knowledge  obtained  by  means  of  Intuition  is  of 
two  kinds,  immediate  and  mediate.  The  former  regards 
the  self-evident  and  necessary  properties  and  relations  of 
things:  the  latter  consists  of  inferences  which  are  neces- 
sarily implied  in  other  propositions. 

We  frequently  know  by  Intuition  that  if  one  thing  is 
true,  another  thing  must  be  equally  true.  Thus,  if  I  know 
that  it  is  full  moon,  I  know,  with  perfect  certainty,  that 
it  is  not  new  moon.  Here  is  an  act  <&  Reasoning,  which 
is,  simply  drawing  necessary  inferences,  or  finding  out,  by 
means  of  self-evident  truths,  propositions  that  arc  neces- 
sarily implied  in  others.  To  reason  is,  to  discern  intui- 
tively that  one  thing  necessarily  implies  another,  or  that, 
if  the  former  is  true,  the  other  is  necessarily  and  inevita- 
bly true,  and  cannot  by  possibility  be  false.  That  such 
is  the  nature  of  all  valid  reasoning  appears,  not  only  from 

C 


50  OF  REASONING.  [CHAP.  IT. 

an  analysis  of  the  process,  but  from  the  fact  that  it  can- 
not possibly  be  otherwise.  There  is  no  possible  means 
of  knowing  anything  indirectly,  except  by  discerning 
that  it  is  necessarily  implied  in  something  which  we 
know  directly.  (4) 

In  all  sound  reasoning  the  thing  implying  is  compared 
with  the  thing  implied ;  and  the  necessary  implication  is 
discerned  intuitively.  The  process  may,  indeed,  be  fal- 
lacious, and  the  supposed  inference  may  not,  in  reality, 
be  necessarily  implied :  but  this  is  never  the  case  in  valid 
or  legitimate  reasoning,  which  is  what  we  mean  when  we 
speak  generally ;  and,  even  in  fallacious  reasoning,  the  in- 
ference is  supposed  or  professed  to  be  necessarily  im- 
plied. 

Thus  it  appears  that  Reason,  or  the  faculty  of  reason- 
ing, is  only  Intuition,  applied  to  discover  mediate  knowl- 
edge, or  to  find  out  necessary  consequences,  by  means  of 
self-evident  truths,  and  that  the  cognitions  implied  in  our 
apprehensions  are  as  dependent  on  Intuition  as  on  Ap- 
prehension. 

Whatever  may  be  the  subject,  the  reasoning  process  is 
identical  in  all  cases:  it  is,  always,  simply  discovering 
that  one  thing  necessarily  implies  another.  But  it  is  of 
the  utmost  importance,  because  it  is  requisite  to  the  ac- 
quisition and  retention  of  all  mediate  knowledge. 

The  general  principle  of  all  reasoning  is,  that  wherever 
one.  thing  necessarily  implies  another,  the  existence  of  the 
former  conclusively  proves  that  of  the  latter,  the  neces- 
sary implication  being  always  discerned  by  Intuition.  It 
maybe  otherwise  expressed  thus:  wherever  one  proposi- 
tion necessarily  implies  another,  the  latter  is  true  if  the 
former  he  true.  The  conclusiveness  of  such  inferences  is 
evidently  independent  of  the  actual  truth  of  the  imply- 
ing propositions :  we  may  draw  necessary  inferences  from 
a  proposition  that  is  merely  assumed  or  supposed  to  be 
true,  as  well  as  from  one  which  actually  is  so.  This  pro- 
ceeding is  frequently  of  the  utmost  importance,  although, 
in  order  to  avoid  error,  we  must  distinguish  it  from 
those  cases  in  which  the  implying  propositions  should  be 
actual  truths. 

A  single  act  of  reasoning  is  called  a  syllogism.  Every 
syllogism  necessarily  consists  of  three  parts,  and  no  more, 
which  maybe  designated  as  follows — (1)  the  premise,  or 
implying  proposition — (2)  the  inference,  or  proposition 


SEC.  1.]          NATURE,  <fcc.,  OF  REASONING.  51 

necessarily  implied — and  (3)  the  connective,  or  self-evi- 
dent truth  by  which  we  know  that  the  inference  is  nec- 
essarily implied  in  the  premise.  (5) 

A  syllogism  may  be  expressed  in  various  ways,  as  its 
parts  may  be  differently  expressed  or  arranged.  The 
connective  may  be  expressed  in  a  more  or  less  general, 
or  in  a  particular  form ;  and  the  other  parts  are,  of  course, 
susceptible  of  the  usual  variety  of  expression.  The  fol- 
lowing may  serve  as  an  example  of  these  variations. 


"1.  Everything  that  thinks,  exists : 
I  think ; 


Therefore  I  exist. 


Connective) 

Premise) 

Inference} 


2.  I  think ;  therefore  I  exist :  for  whatever  thinks  ex- 
ists. 

3.  I  know  intuitively  that  if  I  think  I  exist :  but  that  I 
think  is  a  matter  of  immediate  consciousness ;  therefore 
I  exist. 

4.  I  exist :  for  I  think ;  and  whatever  thinks  exists. 

5.  It  is  self-evident  that  whatever  thinks,  exists :  there- 
fore I  exist ;  for  I  am  directly  conscious  of  thinking. 

0.  I  am  immediately  conscious  of  thinking ;  and  what- 
ever thinks  must  exist :  therefore  I  exist. 

V.  I  certainly  exist :  for  every  being  that  thinks  ex- 
ists ;  and  I  know,  by  direct  consciousness,  that  I  think. 

In  stating  a  syllogism,  the  best  arrangement  is  that 
which  exhibits  most  clearly  the  necessary  connection  be- 
tween the  premise  and  the  inference ;  and  there  is  often 
little  to  choose,  between  several  modes.  The  connective 
is  frequently  suppressed  in  discourse,  because  the  mind 
can  generally  supply  it,  as  it  is  suggested  or  rendered 
obvious  by  comparing  the  premise  and  the  inferences. 
Thus  the  above  syllogism  may  be  expressed" I  think: 
therefore  I  exist."  The  premise,  also,  is,  in  many  cases, 
not  distinctly  expressed,  as  it  is  presumed  to  be  well 
known  to  the  party  addressed,  or  to  be  apparent  from 
the  preceding  assumptions.  So  the  inference  is  often 
omitted,  where  it  is  presumed  to  be  well  known,  and  the 
question  only  regards  the  proof.  But  wherever  there  is 
any  difficulty  or  doubt,  every  part  of  the  syllogism  should 
be  expressed. 

Where  a  premise  is  acknowledged  to  be  true,  it  may 
be  assigned  as  a  proof  of  the  inference ;  and,  in  such 
cases,  it  is  frequently  termed  the  reason  for  it. 


52  OF  REASONING.  [€HAP.  II. 

§  2.  SPECIAL  PRINCIPLES  OF  REASONING. — Definition  and  Nature  of 
these  Principles. — Their  number. — (A)  Definition  and  two  gener- 
al expressions  of  Truisms. — Eight  principal  modifications  of  these. 
— (B)  Seventeen  principles  relating  to  duration  and  extension. — 
'  (C)  Forty-seven  principles  relating  to  abstract  quantity. — (D)  Def- 
inition of  Being,  and  of  various  kinds  of  Beings. — Necessary  and 
contingent  properties. — Seventeen  principles  regarding  the  necessa- 
ry  properties  of  substances  in  general. — Motion,  Force,  and  Change. 
— Necessary  property  of  Inanimate  Beings. — Six  principles  regard- 
ing the  necessary  properties  of  Living  Beings. — Thought. — Belief. 
— (E)  Twenty  principles  regarding  Determining  Conditions  and 
Agencies  in  general. — Causes  and  Effects. — How  these  are  distin- 
guished from  uniform  Antecedents  and  Consequents. — Nine  prin- 
ciples regarding  Desires  and  Volitions.— (F)  Eighteen  principles 
of  Inclusion  and  Exclusion. 

The  special  principles  of  reasoning  are,  those  self-evi- 
dent and  universal  truths  which  are  essential  to  reason- 
ing, and  which  we  may  rightly  employ  either  as  premises 
or  connectives,  in  any  argument  or  investigation.  As  all 
reasoning  is  only  an  application  of  Intuition,  and  intui- 
tions are  the  only  self-evident  and  universal  truths  that 
we  can  know,  it  follows  that  these  are  the  only  legitimate 
principles  of  reasoning.  A  complete  enumeration  of  them 
is  neither  practicable  nor  desirable,  since  their  number  is 
indefinite,  and  many  of  them  are  of  very  little  use:  but 
the  more  important  of  them  are  stated  under  one  or  oth- 
er of  the  following  heads. 

A.  Truisms. 

A  truism  is  a  proposition  in  which  the  predicate  or  a 
part  of  it,  is  asserted  of  itself,  as — "a  man  is  a  man,"  and 
— "  a  Frenchman  is  a  man." 

The  general  formulas,  or  expressions,  of  all  truisms  are, 
that  a  thing  is  equivalent  to  itself,  and  that  every  part  of 
«i  thing  belongs  to  it.  These  are  susceptible  of  innumer- 
able modifications,  of  which  the  following  are  among  the 
principal : 

1.  A  thing  is  not  different  from  itself. 

2.  Different  things  are  not  the  same  thing. 

3.  A  whole  is  equivalent  to  all  its  parts.     As  "  all  the 
parts"  are  the  same  as  "the  whole,"  this  expression  is 
the  same  as  saying  that  a  whole  is  equivalent  to  itself. 

4.  Incompatibilities  cannot  coexist.     This  is  only  say- 
ing in  other  words  that  things  which  cannot  coexist  can- 
not do  so.     What  these  are,  must  be  learned  from  other 
sources. 


SEC.  2.]  -  SPECIAL  PRINCIPLES  OF  REASONING.  53 

5.  Propositions  which  have  the  same  amount  and  kind 
of  proof,  are  equally  credible.    Hence,  if  one  of  such  prop- 
ositions is  unproved,  all  are  unproved ;  if  one  is  estab- 
lished, all  are  established  ;  and  if  one  is  believed,  all  are 
equally  entitled  to  belief. 

6.  The  character  of  a  proposition  is  identical  with  that 
of  others  tantamount  to  itself.     Therefore  the  former  is 
true,  false  or  doubtful,  according  as  the  latter  have  been 
found  to  possess  any  of  these  properties.     This  principle 
enables  us  to  vary  the  forms  of  expressions  without  al- 
tering the  signification,  and  to  combine  many  proposi- 
tions into  one,  which  is  equivalent  to  the  whole  of  them 
taken  together.     For  it  applies  equally  to  cases  where 
one  proposition  is  tantamount  to  another,  and  to  those 
where  it  is  equivalent  to  several,  which  it  comprises. 

7.  Every  proposition  whose  predicate  correctly  ex- 
presses the  thing  denoted  by  its  subject,  is  necessarily 
true ;  and  so  is  its  converse.     If  azote  denote  the  same 
substance  which  is  otherwise  termed  nitrogen,  it  must  be 
true  that  "  azote  is  nitrogen,"  and  equally  true  that  "  ni- 
trogen is  azote."     So  if  it  be  true  that  "  London  is  the 
capital  of  the  British  empire,"  it  is  equally  true  that  "the 
capital  of  the  British  empire  is  London." 

8.  Every  proposition  which  declares  that  a  part  of 
the  subject  belongs  to  it,  is  necessarily  true.     Thus,  "  a 
Frenchman  is  a  man" — "  a  horse  is  a  quadruped,"  and 
"  an  eagle  is  a  bird." 

J3.  Principles  relating  to  Duration  and  Extension^  or 
Abstract  Time  and  Space. 

1.  Duration  and  extension  necessarily  exist. 

2.  They  are  immutable,  and  independent  of  every  other 
thing. 

3.  Every  change  occurs  in  time  and  space. 

4.  All  their  attributes  are  unaffected  by  any  other 
thing,  or  by  any  change.     The  parts  of  duration  succeed 
each  other  uniformly,  beyond  the  power  of  control,  and 
can  neither  be  accelerated  nor  retarded.     So,  extension 
is  unaffected  by  the  bodies  that  may  occupy  portions  of 
it,  or  pass  through  it. 

5.  Both  are  incapable  of  either  motion  or  thought. 

6.  They  cannot  originate  any  change  or  motion. 

7.  They  are  imponderable,  or  without  weight. 

8.  They  cannot  affect  any  of  our  senses.     We  cannot 
feel,  t"sfe,  smoll,  see,  or  hear  either  time  or  sp.neo. 


54  •  OF  REASONING.  [CHAP.  II. 

9.  All  the  parts  of  each  are  homogeneous,  or  exactly 
alike  in  kind. 

10.  Every  part  of  the  one  coexists  with  every  part  of 
the  other.     Every  part  of  time  exists  every  where,  and 
every  part  of  space  exists  always. 

11.  Their  natures  are  essentially  different;  and  one 
cannot  possibly  pass  into  the  other.     Time  possesses  no 
extension,  and  the  parts  of  space  never  come  into  exist- 
ence, nor  cease  to  exist. 

12.  Every  part  of  duration  is  preceded  and  followed 
by  other  parts  of  it;  and  therefore  it  is  eternal,  or  with- 
out beginning  or  end. 

13.  Every  part  of  extension  is  surrounded  by  other 
parts  of  it ;  and,  therefore,  it  is  infinite,  or  without  any 
bounds.  (6) 

14.  Duration  consists  of  parts  which  come  into  exist- 
ence successively,  and  then  cease  to  be  forever ;   and 
hence  no  two  of  them  can  coexist,  nor  can  any  of  them 
which  has  ceased  to  exist,  return,  or  exist  again. 

15.  The  parts  of  extension  all  lie  without  each  other; 
and,  therefore,  no  two  of  them  can  coincide. 

16.  Extension  has  position,  but  not  form;  and  dura- 
tion has  neither  position  nor  form. 

17.  Extension    possesses    mathematical    solidity,  or 
length,  breadth  and  thickness ;  but  it  does  not  possess 
resistive  solidity,  or,  in  other  words,  it  can  offer  no  re- 
sistance to  the  motions  of  bodies  in  any  direction;  dura- 
tion possesses  no  solidity  of  any  kind. 

C.  Principles  relating  to  Abstract  Quantity. 

1.  Abstract  numbers  are   illimitable  in  amount,  and 
homogeneous  in  kind. 

2.  Abstract  magnitudes  are   endlessly  diversified   in 
form  and  size ;  and  they  consist  of  at  least  four  essen- 
tially different  kinds — solids,  surfaces,  lines,  and  angles. 

3.  A  solid  has  three  dimensions — length,  breadth,  and 
thickness. 

4.  A  surface  has  only  two  dimensions — length  and 
breadth ;  and  it  may  be  considered  the  boundary  of  a 
solid. 

5.  A  line  has  only  one  dimension — length ;  and  it  may 
be  considered  the  boundary  of  a  surface. 

6.  A  point  has  no  magnitude,  but  only  position ;  and 
it  may  be  considered  the  extremity  or  end  of  a  line. 


SEC.  2.J     SPECIAL  PRINCIPLES  OF  REASON  ING.  5.5 

7.  A  plane  angle,  or  one  formed  by  two  straight  lines 
meeting  in  a  point,  indicates  only  the  difference  of  direc- 
tion of  its  two  bounding  lines,  which  is  the  sole  measure 
of  its  dimension. 

8.  The  dimensions  of  a  plane  angle  may  be  determined 
by  the  number  of  aliquot  parts  of  a  circular  circumfer- 
ence intervening  between  its  two  bounding  lines,  the 
center  of  the  circle  being  at  the  angular  point. 

9.  A  solid  angle,  or  one  formed  by  three  or  more  plane 
surfaces  which  meet  in  a  point,  termed  its  apex,  indicates 
only  the  differences  of  direction  of  its  bounding  planes, 
which  are  the  sole  measure  of  its  dimension.     Planes, 
or  plane  surfaces,  are  those  which  are  quite  straight,  and 
free  from  any  curve  or  bend,  in  every  direction. 

10.  The  dimension  of  a  solid  angle  may  be  determined 
by  the  number  of  aliquot  parts  of  a  spherical  surface  in- 
cluded between  its  bounding  planes,  the  center  of  the 
sphere  being  at  its  apex. 

11.  Number  and  magnitude  are  essentially  different; 
but  the  latter  may  be  measured  by  the  former. 

12.  Abstract  quantity  has  no   substantial  existence; 
and,  therefore,  its  nature  and  primary  attributes  can  be 
known  only  by  Intuition. 

13.  Magnitudes  are  extended,  and  have  form,  size,  and 
position.    Numbers  possess  none  of  these  ;  they  are  only 
so  many,  and  can  occupy  no  part  of  extension. 

14.  The  whole  includes  all  its  parts  ;  and  the  latter  are 
included  in  the  former. 

15.  The  whole  is  greater  than  a  part ;  and  a  part  is  less 
than  the  whole. 

16.  Magnitudes  which  can  be  made  to  coincide,  are 
equal. 

17.  If  one  of  two  homogeneous  quantities  is  neither 
greater  nor  less  than  the  other,  it  is  equal  to  it. 

18.  Things  equal  to  the  same  thing,  or  to  equals,  are 
equal. 

19.  If  equals  be  affected  by  equals,  the  results  will  be 
equal.     This  principle  comprises  many  others  less  gener- 
al, of  which  the  five  following  are  the  most  important. 

20.  If  equals  be  added  to  equals,  the  sums  will  be  equal. 

21.  If equals  be  subtracted  from  equals,  the  remainders 
will  be  equal. 

22.  If  equals  be  multiplied  by  equals,  the  products  will 
be  equal. 


50  OF  REASONING.  [CHAP.  II. 

23.  If  equals  lie  divided  by  equals,  the  quotients  will 
be  equal. 

24.  Like  powers  or  roots  of  equals  are  equal. 

25.  If  unequals  be  affected  by  equals,  the  results  will 
be  unequal.     This  principle  comprises  the  five  following 
ones. 

26.  If  equals  be  added  to  unequals,  the  sums  will  be 
unequal;  and  that  which  includes  the  greater  element 
will  be  the  greater  sum. 

27.  If  equals  be  subtracted  from  unequals,  the  remain- 
ders will  be  unequal ;  and  the  greater  quantity  will  leave 
the  greater  remainder. 

28.  If  unequals  be  multiplied  by  equals,  the  products 
will  be  unequal;  and  the  greater  multiplicand  will  give 
the  greater  product. 

29.  If  unequals  be  divided  by  equals,  the  quotients  are 
unequal ;  and  the  greater  dividend  gives  the  greater  quo- 
tient. 

30.  Like  roots  or  powers  of  unequals  are  unequal ;  and 
the  greater  quantity  gives  the  greater  root  or  power. 

31.  If  .the  same  operations  be  performed  on  several 
quantities,  the  results  will  bear  to  each  other  the  same 
relations  as  the  original  quantities.     This  principle  com- 
prises the  19th  and  25th,  but  it  is  less  explicit. 

32.  If  equals  be  affected  by  unequals,  the  results  will  be 
unequal.     This  principle  is  the  converse  of  the  25th,  and 
comprises  the  five  following  subordinates. 

33.  If  unequals  be  added  to  equals,  the  sums  will  be  un- 
equal ;  and  the  greater  is  that  which  includes  the  great- 
er element. 

34.  If  unequals  be  subtracted  from  equals,  the  remain- 
ders will  be  unequal ;  and  the  greater  remainder  is  that 
which  is  left  by  subtracting  the  smaller  quantity. 

35.  If  equals  be  multiplied  by  unequals,  the  products 
will  be  unequal;   and  the  greater  multiplier  gives  the 
greater  product. 

36.  If  equals  be  divided  by  unequals,  the  quotients  will 
be  unequal ;  and  the  greater  divisor  will  give  the  smaller 
quotient. 

37.  Unlike  roots  or  powers  of  equals  are  unequal;  the 
lower  root  of  every  number  greater  than  unity  is  greater 
than  the  higher ;  and  the  higher  power  of  every  such 
number  is  greater  than  the  lower. 

38.  A  straight  line  is  wholly  in  one  direction.     Hence, 


,SEC.  2.]     SPECIAL  PRINCIPLES  OF  REASONING.  57 

it  has  two  extremities  or  ends ;  it  can  never  return  into 
itself,  however  far  produced  or  extended;  nor  can  it  in- 
close a  space ;  and  only  one  straight  line  can  be  drawn 
from  one  point  to  another. 

39.  A  straight  line  may  be  indefinitely  produced,  or 
lengthened,  from  either  extremity. 

40.  Two  straight  lines  cannot  coincide  in  two  points 
without  forming  one  straight  line.     Hence  two  straight 
lines  cannot  inclose  a  space :  otherwise  one  straight  line 
might  do  so. 

41.  A  straight  line  is  the  shortest  that  can  be  drawn 
from  one  point  to  another.     Hence  any  two  sides  of  a 
triangle  are  together  greater  than  the  third. 

42.  Straight  lines  which  intersect  or  cut  one  another, 
lie  in  different  directions,  and  diverge  indefinitely,  as  they 
are  produced.     Hence  straight  lines  which  lie  in  the  same 
direction  will  never  meet,  however  far  produced ;  for  oth- 
wise  they  would  lie  in  different  directions. 

43.  The  position  of  a  straight  line  is  wholly  determ- 
ined by  any  two  points  in  it,  or,  in  other  words,  the  po- 
sition of  a  straight  line  cannot  be  in  the  least  changed, 
as  long  as  any  two  points  in  it  continue  in  the  same  po- 
sition. 

44.  The  direction  of  a  straight  line  in  a  plane  is  whol- 
ly determined  by  the  angle  which  it  makes  with  another 
fixed  straight  line  in  that  plane ;  and,  conversely,  the 
size  of  the  angle  is  wholly  determined  by  the  direction 
of  the  two  straight  lines.     Hence  straight  lines  which  are 
in  a  plane,  and  make  equal  angles  with  another  straight 
line  in  that  plane,  lie  in  the  same  direction,  and,  there- 
fore, can  never  meet,  though  produced  ever  so  far  ;  and 
straight  lines  in  a  plane  which  never  meet,  make  equal 
angles  with  another  straight  line  which  they  intersect. 

45.  Two  straight  lines  which  lie  in  different  directions, 
or  make  unequal  angles  with  a  third  straight  line,  and 
are  in  the  same  plane,  will  meet,  if  produced  indefinitely. 

46.  Two  straight  lines  in  the  same  plane  which  are  in- 
clined to  each  other,  or  nearer  at  one  point  than  at  anoth- 
er, will  meet,  if  indefinitely  produced.     Hence  straight 
lines  in  a  plane  which  never  meet,  however  far  produced, 
are  parallel,  or  everywhere  equidistant. 

47.  Two  straight  lines  in  a  plane  which  do  not  intersect 
each  other,  and  are  equidistant  at  any  two  points,  lie  in 
the  same  direction;  and,  therefore,  will  never  meet,  how- 

02 


58  OF  REASONING.  [CHAP.  II. 

ever  far  produced,  and,  therefore,  are  everywhere  equi- 
distant. 

J).  Principles  regarding  the  necessary  properties  of  Sub- 
stantial Beings. 

A  Being  is,  whatever  is,  was,  or  will  be.  Beings  are 
unsubstantial  and  substantial.  The  former  consist  of 
those  which  are  incapable  of  action  or  passion,  including 
duration  and  extension,  and  the  states,  properties  or  re- 
lations of  substantial  beings :  the  latter  comprise  all  oth- 
er beings.  Substances  are  either  material  or  immaterial. 
The  former  are,  those  which  directly  affect  one  or  more 
of  our  senses,  such  as  iron,  water  and  air:  the  latter  com- 
prise all  those  which  do  not  so  affect  any  of  our  senses, 
such  as  the  minds  or  souls  of  men.  Substances  are  also 
divided  into  inanimate  and  animate,  or  living.  The  for- 
mer are  incapable  of  thought :  the  latter  either  think  or 
have  the  power  of  .doing  so. 

The  attributes  or  properties  of  substances  are  of  two 
kinds : — The  necessary,  which  every  substance  must  pos- 
sess, and  which  are  known  only  by  means  of  Intuition ; — 
and  the  contingent,  which  a  substance  may  or  may  not  pos- 
sess, and  which  are  learned  by  means  of  Comprehension. 

The  following  are  the  principal  necessary  properties 
of  substances. 

1.  Every  substance  possesses  resistive  solidity,  the  na- 
ture of  which  is  discerned  intuitively. 

2.  Every  substance  is  extended  in  space,  and  exists  in 
time,  past,  present  or  future ;  or,  in  other  words,  it  must 
occupy  some  portion  of  space,  and  exist  during  some  por- 
tion of  time. 

3.  Every  substance  is  numerically  one,  and  can  occupy 
only  one  part  of  space,  at  any  instant  of  time :  in  other 
words,  it  cannot  be  two  substances,  nor  be  in  two  dis- 
tinct places  at  once. 

4.  Every  substance  possesses  form  and  magnitude,  or 
it  must  have  some  shape  and  size ;  and  it  can  have  only 
one  form  and  size  at  any  instant. 

5.  The  solid  particles  of  substances  are  incompressible 
and  inextensible,  or,  in  other  words,  their  mass  or  quan- 
tity of  solid  substance  can  neither  be  increased  nor  di- 
minished, and  much  less  annihilated.     Bodies  apparently 
solid  are  frequently  compressed;  but  this  arises  from 
their  being  porous. 


SEC.  2.]     SPECIAL  PKINCIPLES  OF  REASONING.  59 

6.  Substances  are  impenetrable,  or,  in  other  words,  two 
substances  cannot  occupy  the  same  part  of  space  at  the 
same  instant. 

7.  Every  substance  must  be  either  at  rest  or  in  motion, 
although  it  may  be  relatively  at  rest,  and  absolutely  in 
motion,  like  a  mountain,  which  partakes  of  the  motions 
of  the  earth,  though  it  is  relatively  at  rest. 

8.  Every  substance  is  mobile,  or  susceptible  of  motion. 

9.  All  motion  consists  of  a  substance's  passing  from 
one  part  of  space  to  another; 

10.  Every  motion  is  performed  in  time,  or,  in  other 
words,  no  motion  is  instantaneous. 

11.  Every  motion  of  a  substance  is  from  that  part  of 
space  where  it  is  to  that  which  is  immediately  contigu- 
ous.    Consequently  every  substance  which  is  found  in  a 
place  different  from  one  which  it  formerly  occupied, 
must  have  passed  continuously  through  every  part  of. 
space  along  some  course  joining  the  two  positions. 

12.  A  substance  impelled  by  a  force  moves  in  the  di- 
rection in  which  it  is  thus  impelled,  or,  in  other  words,  it 
moves  in  the  direction  in  which  it  is  made  to  move.     A 
force  is  anything  which  changes,  or  tends  to  change,  a 
substance's  previous  state  of  rest  or  motion. 

13.  Force  is  requisite  to  change  a  substance's  state  of 
rest  or  motion. 

14.  The  velocity,  or  speed,  of  a  substance  is  proportion- 
al to  the  force  which  generates  it,  if  there  is  no  counter 
action  or  interference  of  any  other  force. 

15.  A  substance  affected  by  several  forces  which  do 
not  counteract  each  other,  moves  as  if  it  were  affected 
by  one  force  equivalent  to  them  all. 

16.  Substantial  beings  alone  are  susceptible  of  change, 
this  term  being  understood  in  its  ordinary  signification  ; 
and  every  change  consists  of  the  motion  of  a  substance 
from  one  part  of  space  to  another. 

17.  Substantial  beings  alone  are  capable  of  thinking, 
or  originating  motion,  although  all  beings  of  that  class 
may  not  possess  that  power. 

18.  Inanimate  substances  can  have  no  desire  or  aver- 
sion*     Hence  they  cannot  be  influenced  by  motives,  or 
originate  any  change,  and  they  can  produce  or  undergo 
a  change  only  where  they  are  affected  by  some  other 
agent,  unless  we  assume  that  they  were  in  motion  from 
all  eternity. 


CO  OF  REASONING.  [CHAP.  II. 

Of  the  necessary  properties  of  living  beings,  the  fol- 
lowing are  the  principal. 

1.  Every  living  being  is  at  least  capable  of  thought, 
although  he  may  possibly  never  have  .actually  thought. 

2.  Every  thought  is  real,  and  the  act  of  a  living  being. 

3.  Every  thought  is  precisely  what  it  appears  to  be  to 
the  thinker.     We  must  distinguish  the  thought  from  its 
object  or  cause,  which  may  be  different  from  what  AVC 
believe  it  to  be ;  but  this  does  not  in  the  least  affect  the 
character  of  the  thought. 

4.  The  presence  'or  absence  of  thought  is  precisely  as 
the  thinker  believes.     We  cannot  believe  that  we  do  not 
think  when  we  do,  nor  that  we  think  when  we  do  not. 

5.  Belief  loithout  grounds  satisfactory  to  the  believer, 
is  impossible,  real   and  not  professed  belief  being,  of 
course,  understood.     The  grounds  of  belief  may,  in  real- 
ity, be  conclusive ;  yet  if  they  do  not  appear  to  the  indi- 
vidual of  any  weight,  he  will  inevitably  disbelieve. 

6.  Belief  against  grounds  satisfactory  to  the  believer 
is  impossible.     The  proofs  may  be  really  worthless ;  yet 
if  they  appear  satisfactory  to  the  believer,  he  will  neces- 
sarily believe. 

E.  Principles  relating  to  determining  Conditions  and 
Agencies. 

1.  Where  the  conditions  which  determine  results  are 
the  same,  the  results  will  be  the  same,  however  much 
other  things  may  vary,  the  word  "  same"  being  taken  to 
mean  either  absolute  identity  or  perfect  similarity.     The 
determining  conditions  are,  those  things  which  determ- 
ine, limit  or  fix  a  thing  to  be  what  it  is,  and  not  different. 

2.  Where  the  determining  conditions  are  different,  the 
results  will  be  different,  although  other  things  should  be 
the  same. 

3.  Any  proposition  established  in  one  case,  independ- 
ently of  particular  circumstances,  holds  true  of  all  cases 
which  differ  only  in  these  circumstances. 

4.  What   has   once  happened,  must   always  happen, 
wherever  all  the  circumstances  which  influence  the  result 
are  the  same. 

5.  Every  change  is  preceded  or  accompanied  by  mo- 
tion of  one  or  more  beings ;  and  change  without  motion 
is  impossible. 

6.  Every  change  must  have  its  ultimate  origin  either 


SEC.  2.]     SPECIAL  PRINCIPLES  OF  REASONING.  Gl 

in  the  volition  of  a  thinking  being,  or  in  a  substance 
which  was  previously  in  motion  from  all  eternity. 

7.  Every  change  is  necessarily  preceded  by  something 
which  produces  it,  or  on  which  it  is  dependent,  called  its 
Cause,  and  with  reference  to  which  it  is  termed  wo.  Effect ; 
or,  in  other  words,  everything  which  begins  to  be,  is  pre: 
ceded  by  something  which  makes  it  be,  and  failing  which 
it  would  not  be.     The  effect  being  dependent  on  the 
cause,  distinguishes  the  latter  from  a  uniform  antecedent, 
and  the  former  from  a  uniform  consequent. (7) 

8.  Nothing  can  produce  only  nothing,  which  may  be 
otherwise  expressed,  something  cannot  spring  from  noth- 
ing. 

9.  In  order  to  produce  a  change,  a  cause  must  be  ade- 
quate to  produce  it :  but  what  are  adequate  causes  must 
generally  be  learned  from  other  intuitions,  and  from  ex- 
perience. 

10.  Where  a  cause  known  to  operate,  is  found  inade- 
quate to  produce  the  whole  of  an  effect,  the  residue  is 
owing  to  some  other  cause. 

1 1 .  An  agent  cannot  act  where  it  is  not  /  or,  in  other 
words,  an  agent  can  produce  no  effect  where  it  is  not, 
except  by  some  medium.     The  Sun  produces  effects  on 
the  Earth  by  the  mediums  of  light  and  heat,  without 
which  we  could  neither  see  it  nor  feel  its  warmth. (8) 

12.  "When  two  sets  of  agencies  or  forces  operate,  which 
tend  to  produce   precisely  similar  effects,  but  directly 
counteract  each  other,  the  one  set  nullifies  the  other,  and 
no  such  effect  ensues,  which  may  be.  more  briefly  express- 
ed thus :  equal  and  contrary  forces  neutralize  each  other. 

13.  The  same  cause,  operating  in  the  same  circum- 
stances, always  produces  the  same  effect. 

14.  An  effect  which  depends  solely  on  a  particular 
cause,  varies  in  proportion  to  the  changes  in  the  cause, 
and  conversely ;  or,  in  other  words,  effects  are  propor- 
tional to  their   causes,  and  the  intensity  of  a  cause  is 
measured  by  the  effect.     Hence,  where  the  result  is  ap- 
parently otherwise,  one  or  more  additional  agencies  must 
be  concerned  in  its  production ;  and  this  is  so  frequently 
the  case  that  an  appeal  to  -experience  is  generally  requi- 
site, before  we  are  warranted  in  assuming  that  no  such 
second  agency  is  concerned. 

15.  Where  several  agencies  or  forces  exactly  co-operate 
-or  combine,  to  produce  a  particular  effect,  the  result  is 


62  OF  REASONING.  [CHAP.  II. 

the  same  as  would  be  produced  by  a  single  agency  equal 
to  the  sum  of  those  agencies. 

16.  A  body,  or  a  connected  system  of  bodies,  is  in  equi- 
librium when  the  forces  which  tend  to  move  it  in  a  cer- 
tain direction  are  equal  to  those  which  tend  to  move  it 
in  the  contrary  direction.    By  a  "  body"  is  understood  a 
material  substance. 

17.  Where  a  body  is  urged  in  contrary  directions  by 
unequal  forces,  it  will  move  in  the  direction  in  which  it 
is  impelled  by  the  stronger  force,  as  if  it  were  affected  by 
a  single  force  equal  to  their  difference. 

18.  When  the  cause  ceases  to  act,  its  effect  ceases  to  be 
produced.     This  principle  must  not  be  confounded  with 
the  very  different  proposition  that  an  effect  already  pro- 
duced will  cease  to  exist  when  the  producing  cause  ceases 
to  operate ;  a  proposition  which  is  not  even  true.     A 
change  already  produced  may  be  permanent,  or  produce 
farther  changes,  although  its  cause  may  become  inopera- 
tive, or  even  cease  to  exist.     Thus,  if  a  man  ruins  his 
health  by  dissipation,  it  is  not  immediately  restored  when 
he  ceases  to  dissipate,  and  perhaps  never;  yet  it  is  self- 
evident  that,  when  he  ceases  from  his  bad  habits,  he  will 
suffer  no  further  injury  directly  from  that  cause. 

19.  The  presence  or  absence  of  the  cause  proves  the 
presence  or  absence  of  the  effect,  provided  there  is  no 
counteracting  or  interfering  agency. 

20.  The  presence  or  absence  of  the  effect  proves  the 
presence  or  absence  of  the  cause,  if  the  former  has  not 
been  removed  by  some  extraneous  agency. 

The  following  are  the  most  important  principles  re- 
garding desires  and  volitions : 

1.  A  regard  to  good  and  evil  is  the  only  cause  of  the 
free  or  voluntary  acts  of  living  beings. 

2.  Every  volition,  or  act  of  will,  has  for  its  object  the 
greatest  apparent  good;  or,  in  other  words,  the  greatest 
apparent  good  is  always  willed.    By  the  greatest  appar- 
ent good  is  meant  that  which  the  individual  believes  to 
be  such,  although  it  is  frequently  by  no  means  the  great- 
est real  good. 

3.  That  which  will  apparently  secure  more  good,  is 
willed  before  that  which  is  believed  to  secure  less;  and 
where  one  of  two  evils  is  deemed  inevitable,  that  which 
appears  the  less  is  willed. 

4.  Every  apparent  good  is  an  object  of  desire ;  and  ev- 
every  apparent  evil  is  an  object  of  aversion. 


SEC.  2.]    SPECIAL  PRINCIPLES  OF  REASONING.  G3 

5.  Where  there  is  no  'knowledge  or  belief  regarding 
good  or  evil,  there  can  be  no  volition  or  voluntary  action. 

6.  Where  the  apparent  good  and  evil  .ire  precisely 
equal,  there  can  be  no  volition  or  voluntary  action. 

7.  Where  two  objects  appear,  in  every  respect,  equally 
good,  there  can  be  no  choice. 

8.  Every  voluntary  action  conforms  to  the  decision  of 
the  Judgement  which  pronounces  it  a  means  towards  the 
greatest  good. 

9.  A  change  of  the  Judgement  or  of  belief,  regarding 
good  and  evil,  is  followed  by  a  corresponding  change  of 
volition. 

F.  Principles  of  Inclusion  and  Exclusion. 

1.  A  thing  cannot  be,  and  yet  at  the  same  time  and  in 
the  same  sense,  not  be. 

2.  An  attribute  cannot  be  truly  affirmed  and  denied  of 
a  thing,  at  the  same  instant. 

3.  No  being  can  possess  either  contradictory  or  incom- 
patible attributes  or  properties. 

4.  Of  two  contradictory  propositions,  one  must  be  trite 
and  the  other  false.     Hence,  if  one  is  true,  the  other  is 
false,  and  conversely. 

5.  Of  two  contrary  propositions,  both  cannot  be  true, 
but  both  may  be  false.    It  is  not  generally  necessary  that 
a  being  should  possess  either  of  two  contrary  attributes, 
but  it  cannot  possess  both.     Thus,  the  sky  is  neither 
white  nor  black;  but  if  it  were  the  one,  it  could  not  be 
the  other. 

6.  A  proposition  cannot  be  both  true  and  false,  in  the 
same  sense.     Hence,  if  one  of  several  propositions  must 
be  true,  and  all  but  one  are  found  to  be  false,  this  one  is 
true.    So,  every  proposition  is  false  which  necessarily  im- 
plies something  incompatible  with  truth  ;  else  the  prop- 
osition implied  would  be  both  true  and  false. 

7.  If  one  thing  includes  a  second,  this  second,  a  third, 
and  so  on,  then  the  first  includes  the  last.    This  principle 
applies  both  to  physical  objects  and  to  inclusion  by  nec- 
essary inference.     Thus,  if  London  is  in  England,  and 
England,  in  Europe,  London  is  in  Europe.     So,  if  all 
kings  are  men,  and  all  men  are  mortal,  then  all  kings  are 
mortal. 

8.  If  one  thing  is  equivalent  to  a  second,  this  second, 
to  a  third,  and  so  on,  any  one  of  the  series  is  equivalent 


C4  OF  REASONING.  [CHAP.  II. 

to  any  other.     As  equals  are  included  under  equivalents, 
this  principle  includes  the  former. 

9.  A  being  possessing  the  characteristic  or  peculiar 
marks  of  a  classes  one  of  that  class;  and  a  being  which 
wants  these  marks,  does  not  belong  to  the  class.     The 
"  characteristic"  or  "peculiar  marks"  of  a  class  are,  those 
properties  which  belong  to  every  individual  of  a  class, 
and  to  no  other  being. 

10.  Every  being  possesses  the  essential  properties  of 
its  class.     Thus,  a  triangle  must  have  three  angles,  and 
an  animal  must  be  alive.     The  "  essential  properties"  of 
a  class  of  beings  are  those  which  distinguish  it  from  all 
others,  and  the  want  of  which  excludes  a  being  from  the 
class. 

11.  The  universal  includes  the  particular  •  or,  in  other 
words,  whatever  belongs  to  a  class  individually,  belongs 
to  every  one  of  that  class ;  and  whatever  is  wanting  in  a 
class  individually,  is  wanting  in  every  one  of  that  class. 
Thus,  if  John  is  one  of  a  class  of  beings  individually  ra- 
tional, he  is  rational ;  and  if  he  is  one  of  a  class  of  ani- 
mals individually  wanting  fins,  he  is  finless.     This  prin- 
ciple enables  us  to  express  a  universal  truth  in  an  indef- 
inite variety  of  less  comprehensive  forms. 

12.  Whatever  belongs  to  every  individual  of  a  class, 
belongs  to  the  class ;  and  whatever  is  wanting  in  every 
individual  of  a  class,  is  wanting  in  the  class. 

13.  If  some  property  of  a  thing  is  proved,  all  incom- 
patible properties  are  disproved.     Thus,  if  it  is  proved 
that  a  certain  man  is  virtuous,  it  is  disproved  that  he  is 
vicious ;  or,  if  it  is  proved  that  he  is  a  cheat,  it  is  dis- 
proved that  he  is  honest. 

14.  An  exclusive  and  uniform  consequent,  concomitant 
or  antecedent  of  a  phenomenon,  proves  its  past,  present 
or  future  existence.     This  principle  applies  only  where 
the  connection  of  the  two  things  is  already  known,  which 
is  generally  ascertained  either  by  their  being  necessarily 
connected  as  cause  and  effect,  or  by  their  being  the  ef- 
fects of  a  common  cause. 

15.  A  common  consequent,  concomitant  or  antecedent 
of  a  phenomenon  proves  its  probable  past,  present,  or  fu- 
ture existence :  and  the  probability  varies  according  to 
the  extent  of  the  connection,  which  is  learned  chiefly  by 
previous  experience  of  similar  cases. 

16.  Every  intuition  is  self-evident,  whether  expressed 


&EC.  3.]  PROCESSES  AND  CRITERION'S.  65 

universally,  generally,  or  particularly :  and  hence  it  may 
assume  an  indefinite  number  of  forms,  all  of  which  are 
self-evident,  if  properly  expressed. 

17.  A  thing  either  is  or  is  not.    This  is  the  formula  of 
alternation ;  and  it  is  extensively  employed  to  determine 
all  the  possible  conditions  of  a  problem. 

18.  The  existence  of  a  property  necessarily  implies  the 
existence  of  something  of  which  it  is  the  property ;  and 
a  property  cannot  inhere  in  anything  with  which  it  is  in- 
compatible.    This  principle  is  extensively  applied,  in  its 
special  forms,  in  ascertaining  the  existence  and  qualities 
of  objects. 

§  3.  PROCESSES  Ais7r>  CRITERIONS  OF  REASONING. — Method  of  estab- 
lishing a  Conclusion. — Primary  Premises,  Conclusion,  and  Chain 
of  Reasoning. — Requisites  to  render  a  chain  of  reasoning  valid. — 
Testing  Syllogisms. — Parts  of  it  often  overlooked. — Ultimate  foun- 
dations of  all  valid  reasoning. — Two  modes  of  testing  a  chain  of 
reasoning. — Things  to  be  examined,  in  all  cases. — Effect  of  Am- 
biguity or  Obscurity. — Two  modes  of  proceeding. — Where  both 
should  be  adopted. — Advantages  of  considering  connectives  gener- 
ally.— Allowable  course  where  any  of  the  conditions  of  valid  rea- 
soning are  wanting. — Nature  and  various  kinds  of  Arguments. — 
Collateral  chains  of  Reasoning. — Nature  and  use  of  Combination. 
— Representation  of  a  complex  Argument. — Proving  too  much. — 
Why  the  faculty  of  reasoning  cannot  be  successfully  impugned. — 
Relation  of  Reasoning  to  Language. — Evils  of  not  looking  beyond 
words,  in  reasoning. — How  Memory  and  Language  aid  reasoning. 
— Other  aids. — Judgement,  and  Intellect. 

In  establishing  the  proposition  in  question,  it  is  gener- 
ally requisite  to  proceed  by  degress :  the  first  proposi- 
tion, which  we  term  the  primary  premise,  is  discerned  to 
imply  a  second,  this  second,  a  third,  and  so  on,  to  the  last 
inference,  or  conclusion,  the  premise  of  one  syllogism  be- 
ing the  inference  of  the  preceding.  The  whole  series  is 
termed  a  chain  of  reasoning,  the  syllogisms  being  com- 
pared to  links ;  and  it  may  consist  of  an  indefinite  num- 
ber of  these.  The  conclusion  is  always  connected  with 
the  primary  premise  by  means  of  the  seventh  principle 
stated  in  the  last  subdivision  of  the  preceding  section,  al- 
though it  is  so  obvious  that  it  is  rarely  expressed. 

The  nature  of  a  chain  of  reasoning  may  be  exhibited 
to  the  eye  by  the  following  diagram : 


66  OF  REASONING.  [CHAP.  II. 

Primary  premise. 

First  inference  and  second  premise. 
inference  and  third  premise. 


^ 
First  connective     •< 


Second  connective 

>Second 


Third  connective 

>Third  inference  and  fourth  premise. 
Fourth  connective-^ 

VLast  inference,  or  conclusion. 

To  render  a  chain  of  reasoning  valid,  it  must  possess 
the  four  following  characteristics. 

1.  The  primary  premise  must  be  all  that  it  is  rightly 
assumed  to  be.     If  it  is  assumed  to  be  a  discernment,  it 
must  not  be  an  inference  or  a  proposition  founded  on 
testimony  ;  and  if  it  is  assumed  to  be  a  supposition  which 
is  possibly  true,  it  must  not  be  an  impossibility.     So,  if  it 
is  assumed  to  be  proved  by  testimony,  this  must  be  con- 
clusive ;  or  if  it  is  assumed  to  have  been  demonstrated 
by  a  process  of  reasoning,  this  must  be  valid. 

2.  Every  successive  premise  must  be  necessarily  im- 
plied in  that  which  immediately  precedes  it. 

3.  The  conclusion  must  be  the  real  question,  and  not 
one  merely  like  it. 

4.  Every  part  must  be  understood  or  expressed  clearly 
and  accurately,  so  that  there  is  no  room  for  doubt  as  to 
what  the  exact  things  are.     For,  if  this  condition  is  not 
complied  with,  violations  of  the  others  cannot  be  de- 
tected. 

The  strength  of  a  chain  is  not  greater  than  that  of  its 
weakest  part  ;  and  if  one  material  link  fails,  the  whole  is 
worthless. 

In  order  to  test  the  validity  of  a  syllogism,  we  must 
discover  the  three  parts.  This  is  sometimes  a  difficult 
matter  :  for,  not  only  are  those  parts  frequently  separ- 
ated from  each  other  by  wide  intervals,  both  in  spoken 
and  in  written  discourse,  but  we  have  often  to  gather  the 
detached  fragments  of  a  proposition  from  various  quar- 
ters, as  it  is  nowhere  distinctly  stated. 

In  many  cases,  the  rapidity  of  thought  leads  us  to 
overlook,  in  analysing,  some  of  the  syllogisms  of  the 
chain  ;  and  hence,  when  we  endeavor  to  trace  the  steps 
by  which  we  arrived  at  the  conclusion,  flaws  appear  in 
the  chain,  while,  in  reality,  it  was  continuous  and  conclu- 
sive. We  must,  therefore,  beware  of  inferring  that  the 


SEC.  3.]  PROCESSES  AND  CKITEEIONS.  67 

process  by  which  we  arrived  at  the  conclusion  was  cer- 
tainly faulty,  because  we  have  failed  to  make  out  all  the 
links  of  the  chain.  In  many  cases,  a  little  careful  exam- 
ination will  make  the  defective  links  obvious.  Yet  we 
ought  never  to  adopt  conclusions  as  certainly  true  until 
we  obtain  the  evidence  of  consciousness,  at  every  step, 
although  it  is  frequently  difficult,  especially  for  persons 
unaccustomed  to  analyse  thought,  to  retrace  all  the  men- 
tal processes. 

Reasoning  often  starts  with  propositions  that  are  ac- 
knowledged to  be  true  by  the  party  to  whom  it  is  ad- 
dressed: but,  to  render  a  conclusion  absolutely  estab- 
lished, we  must  commence  with  truths  of  immediate  con- 
sciousness, or,  in  cases  of  hypothetical  reasoning,  with 
the  original  suppositions.  For  discernments  and  suppo- 
sitions necessarily  form  the  ultimate  foundations  of  all 
reasoning.  We  cannot  reason  from  infinity;  and  we 
must  begin  with  what  is  self-evident,  or  what,  without 
being  so,  is  known  by  direct  consciousness,  or  with  some- 
thing that  we  assume  or  suppose  to  be  true,  although  it 
may  be  only  a  probability,  or  purely  hypothetical. 

We  may  examine  the  validity  of  a  chain  of  reasoning 
by  tracing  it  from  the  primary  premise  to  the  conclu- 
sion :  or  we  may  begin  with  the  latter,  and  trace  it  back 
to  the  former.  In  both  cases,  we  must  always  examine 
what  the  proposition  under  immediate  consideration  is, 
and  whether  it  is  necessarily  connected  with  those  adja- 
cent. If  an  obscurity  or  ambiguity  occur  in  any  part, 
the  -whole  chain  should  be  held  invalid,  until  the  diffi- 
culty has  been  cleared  up :  for,  otherwise,  we  cannot  as- 
certain whether  the  necessary  connection  exists,  and  soph- 
istry may  occupy  the  place  of  sound  reasoning.  Owing 
to  the  defects  of  language  and  to  loose  or  inaccurate 
thinking,  it  is  sometimes  difficult  to  discover  the  exact 
import  of  a  material  proposition ;  but  this  must  always 
be  done,  before  we  can  ascertain  whether  the  reasoning 
is  valid. 

If  we  begin  with  the  primary  premise,  we  are  first  to 
consider  whether  it  requires  proof.  If  it  does,  the  whole 
chain  is  baseless :  if  not,  we  then  examine  what  the  first 
inference  is,  and  whether  it  is  necessarily  implied  in  the 
premise.  If  so,  we  then  examine  what  the  next  infer- 
ence is,  and  so  on,  till  we  come  to  the  final  conclusion. 
If  this  be  not  the  real  question,  the  whole  chain  is  worth- 
less, since  it  is  beside  the  subject. 


68  OF  REASONING.  [CHAP.  II. 

If  we  begin  with  the  conclusion,  we  first  consider  what 
the  real  question  is,  and  then  ascertain  whether  this  is 
the  very  inference  drawn  from  the  premise  immediately 
preceding.  If  so,  we  then  find  out  this  premise,  and  con- 
sider whether  it  necessarily  implies  the  conclusion.  If 
so,  we  search  for  the  premise  whence  the  former  was  in- 
ferred, and  so  on,  till  we  come  to  the  primary  premise. 

In  cases  of  importance,  it  is  proper  to  try  the  validity 
of  a  chain  of  reasoning  both  ways.  In  determining 
whether  a  premise  really  implies  the  inference  drawn 
from  it,  we  need  not  consider  the  connective  in  a  more 
general  form  than  the  particular  connection  demands : 
but  it  is  desirable  to  understand  its  universal  nature,  as 
we  can  thus,  in  many  instances,  more  clearly  discern  the 
connection,  and  apply  the  principle  more  readily  and  safe- 
ly in  other  cases. 

Wherever  we  find  an  absence  of  any  of  the  four  con- 
ditions of  conclusive  reasoning,  we  need  not  proceed  far- 
ther: for  one  essential  defect  invalidates  the  whole.  A 
chain  of  reasoning  resembles  one  of  iron,  employed  to 
move  a  weight,  which  must  be  sound  in  itself,  attached 
to  a  moving  power  of  sufficient  force,  and  also  fastened 
to  the  proper  weight,  and  which  fails  of  effecting  the 
object  if  there  be  a  delect  in  any  of  these  respects.  The 
case  where  the  moving  power  is  deficient,  or  the  chain 
not  sufficiently  secured  to  it,  corresponds  to  that  of  an 
unsound  or  inadmissible  premise :  that  of  a  weak  or 
broken  chain  corresponds  to  a  flaw  or  obscurity  in  the 
reasoning ;  and  the  case  of  the  chain  being  fastened  to 
the  wrong  weight  answers  to  that  where  the  conclusion 
proved  is  not  the  proposition  in  question. 

An  argument  is,  what  is  employed  to  prove  a  conclu- 
sion. It  may  consist  of  a  single  syllogism :  but  it  is  more 
frequently  made  up  of  several  collateral  chains  of  reason- 
ing, or  a  combination  of  such  chains,  often  blended  with 
matters  which  are  assumed  as  known  or  true — all  con- 
verging towards  the  conclusion.  Some  of  these  chains 
may  be  either  essential  parts  of  the  argument,  or  inde- 
pendent of  the  rest,  and  only  employed  to  corroborate 
or  strengthen  the  conclusion  deduced  from  them. 

Several  primary  premises  are  often  employed  to  prove 
a  more  general  proposition,  which  embraces  them  all, 
and  is  tantamount  to  the  whole  of  them  taken  together. 
When  this  identity  has  been  ascertained,  we  infer  the 


SEC.  3.]  PROCESSES    AND    CuiTERIONS.  60 

"truth  of  the  general  proposition  upon  the  principle  al- 
ready stated,  that  the  character  of  a  proposition  is  iden- 
tical with  that  of  others  tantamount  to  itself.  Several 
of  the  new  propositions,  thus  established,  may  be  em- 
ployed, in  the  same  way,  as  premises  to  prove  a  still 
more  comprehensive  conclusion,  and  so  on,  the  whole 
process  resembling  the  confluence  of  streams,  where  riv- 
ulets flow  together  to  form  brooks,  and  several  of  these 
unite  to  form  rivers,  while  the  independent  parts  may 
be  compared  to  streamlets  that  flow  directly  into  the  sea. 

In  such  cases,  we  first  observe  the  various  things  al- 
ready proved  or  known,  which  we  desire  to  embrace  in 
the  more  general  proposition,  then  search  for  a  suitable 
expression,  which  we  compare  with  them,  in  order  to 
ascertain  whether  it  comprises  them  all  and  no  more. 
When  that  has  been  done,  we  infer  that  the  compre- 
hending proposition  is  true,  and  employ  it  accordingly. 

Such  a  process  may  be  termed  combination.  Although 
it  merely  embraces  in  a  more  general  proposition  partic- 
ular or  narrower  ones  previously  known,  established,  or 
assumed,  yet  it  is  of  much  importance,  as  it  greatly  aids 
Memory  and  Reason  in  establishing  comprehensive  con- 
clusions. Without  such  aid,  the  Attention  and  the  Mem- 
ory would  be  so  confused  that  the  bearings  of  the  previ- 
ous cognitions  could  not  be  discovered,  and  we  should  con- 
sequently be  unable  to  connect  them  with  the  conclusion. 

Every  distinct  part  of  an  argument  is  to  be  tested  in 
the  manner  already  pointed  out,  as  if  it  formed  the  whole. 
But  we  should  carefully  observe  whether  the  things  com- 
bined are  tantamount  to  the  comprehending  proposition 
to  which  they  are  assumed  to  be  equivalent :  for,  in  many 
instances,  they  are  so  only  with  certain  restrictions  or 
modifications,  which  are  apt  to  be  overlooked,  or  they 
contain  less  than  is  assumed.  • 

The  nature  of  a  complex  argument  may  be  illustrated 
by  the  following  figure. 

Intuition        Perception 

.-Premise  (combining  both)  .-Emotional  truth 

Connective  \  Connective  -j 

^Inference     Testimony      Sensation      ^Inference 

i     .      I  I  I 

,•    Premiss 

I  (combination)  Corroborative  Corroborative 

Connective  4  inference  testimony 

^C  onclu  sion ! 


70  OF  REASONING.  [CHAP.  II. 

The  fallaciousness  of  an  argument  sometimes  appears 
from  its  proving  something  which  we  know  to  be  un- 
true, equally  with  the  conclusion  which  it  is  employed  to 
establish.  Arguments  of  this  kind  are  said  to  "prove 
too  much,"  and  are  evidently  invalid :  but  we  must  be- 
ware of  assuming  that  they  are  so,  merely  because  this  is 
alleged  ;  for  opponents  sometimes  make  such  allegations 
when  the  argument  is,  in  reality,  irrefragable.  An  argu- 
ment which  is  conclusive  in  itself,  cannot  possibly  prove 
too  much :  otherwise  the  same  proposition  would  be  both 
true  and  false. 

All  attempts  to  impugn  the  faculty  of  reasoning  are 
fallacious :  for  they  necessarily  assume  its  faithfulness, 
while  they  profess  to  prove  the  contrary.  We  cannot 
proceed  a  step  to  impeach  it,  without  first  assuming  its 
entire  reliability ;  and  if  we  can  trust  its  conclusions  in 
one  case,  we  are  evidently  bound  to  receive  them  in  all 
other  cases  equally  unobjectionable.  A  difficulty  some- 
times occurs  from  its  leading  to  apparently  contradictory 
conclusions :  but,  as  it  is  self-evident  that  contradictions 
cannot  both  be  true,  there  must  be  some  fallacy  in  one 
or  other  of  the  processes,  which  a  careful  examination 
will  always  detect.  Consequently  the  discrepancy  is 
only  apparent;  and  such  difficulties  only  prove  that  we 
are  liable  to  reason  erroneously  or  inconclusively,  a  truth 
of  which  we  have  frequent  proof.  Yet  it  is  possible  to 
test  reasoning,  so  that  we  shall  certainly  know  whether 
it  contains  any  fallacy. 

Although  language  and  other  signs  of  thought  are  fre- 
quently of  the  utmost  use  in  reasoning,  yet  we  cannot 
reason  closely  and  conclusively,  in  all  the  most  difficult 
subjects  of  investigation,  without  discarding  all  such 
signs,  and  directly  considering  the  things  signified  :  oth- 
erwise we  may  possibly  be  reasoning  merely  about  words, 
and  continue  ignorant  of  what  they  profess  to  denote,  a 
thing  which  has  very  frequently  occurred.  Words  are 
merely  signs  of  thought :  and  unless  we  discern  a  neces- 
sary connection  between  the  things  signified,  independ- 
ently of  their  signs,  our  conclusions  may  possibly  hold 
true  only  of  the  latter.  For  words  are  frequently  of 
dark  or  doubtful  import,  or  wholly  unintelligible  to  the 
party  addressed ;  and  the  difficulty  can  be  removed  only 
by  determining  the  nature  and  necessary  relations  of  the 
things  signified,  which  cannot  frequently  be  done  with- 
out considering  them,  wholly  apart  from  language. 


SEC.  1.]  APPREHENSIONS.  71 

Whence  once  we  have  clearly  understood  the  exact 
nature  and  extent  of  the  things  denoted  by  language,  it 
enables  us  to  substitute  signs  or  symbols  for  the  things 
signified ;  and  thus  we  can  arrive  at  conclusions  other- 
wise unattainable,  while,  in  other  cases,  the  process  of 
reasoning  is  greatly  facilitated  and  abridged. 

Memory  aids  reasoning  by  enabling  us  to  substitute 
similitudes  for  their  prototypes,  and  thus  to  reason  about 
things  absent  as  if  they  were  present,  while  language  en- 
ables us  to  discard  even  similitudes,  for  the  time  being, 
and  substitute  in  their  place  mere  visible  or  audible  signs 
or  symbols  of  them.  Such  aids  are  generally  requisite, 
in  order  either  to  establish  or  retain  general  or  recondite 
truths. 

Comprehensions  form  the  starting  point  of  all  knowl- 
edge, since  they  are  requisite  to  rouse  our  intellects  into 
action,  and,  at  the  same  time,  they  furnish  the  funda- 
mental elements  of  all  contingent  knowledge.  Abstrac- 
tion is  also  requisite  in  all  reasoning  regarding  matters 
which  present  any  difficulty.  Hence  the  faculties  of 
Apprehension,  Memory,  Abstraction  and  Reasoning  are 
designated  by  the  common  term  Judgement,  which  dif- 
fers from  Intellect  in  excluding  Conception.  This  faculty 
is  comparatively  feeble  in  the  greater  number  of  man- 
kind, and  much  more  rarely  used  in  discovering  truth. 

The  conclusions  drawn  from  premises  whose  character 
has  been  investigated  by  the  aid  of  the  Judgement,  are 
termed  judgements.  (9) 


CHAPTER  III. 

OF   THE   PRIMARY   MEANS    OF   ACQUIRING   CONTINGENT 
KNOWLEDGE. 

§  1.  REALITY  OP  APPREHENSIONS,  AND  MEANS  OF  AVOIDING  THE  PRI- 
MARY ERRORS  WHICH  THEY  OCCASION. — Origin  of  Errors  attributed 
to  the  Senses. — How  Apprehensions  may  be  distinguished  from 
Ideas. — Specters. — Apprehensions  necessarily  real. — Distinguisha- 
ble from  their  causes. — Inferences  from  them  often  erroneous. — 
How  these  may  be  tested,  and  errors  avoided. 

ALTHOUGH  the  senses  are  frequently  occasions  of  error, 
yet,  strictly  speaking,  they  never  deceive ;  and  all  the  er- 
rors attributed  to  them  arise  either  from  confounding 


72     ACQUIRING  CONTINGENT  KNOWLEDGE.   [CHAP.  III. 

apprehensions  and  ideas,  or  from  drawing  unwarrantable 
inferences  from  the  former. 

To  avoid  errors  of  the  first  class,  it  is  only  requisite  to 
attend  to  the  peculiarities  of  ideas  and  apprehensions. 
The  former  are  readily  distinguished  from  the  latter, 
wherever  the  apprehending  organs  are  sound,  not  only 
by  their  shadowy  and  fleeting  nature,  but  also  by  their 
being  generally  under  the  control  of  the  Will.  If  we 
think  of  a  well-known  tree,  which  is  at  the  moment  in- 
visible, the  likeness  of  it  which  we  discern  is  much  faint- 
er than  if  we  actually  viewed  it ;  and  it  vanishes  alto- 
gether, in  a  very  short  time,  unless  a  conscious  effort 
of  the  Will  detains  it ;  and  if  we  so  will,  it  vanishes  at 
any  instant,  whereas  the  apprehension  is  not  only  much 
stronger  and  more  distinct,  but  it  cannot  be  willed  away, 
while  we  behold  the  tree. 

In  some  cases  of  very  forcible  apprehensions,  or  a  dis- 
eased condition  of  the  organs  of  sense,  ideas  acquire  un- 
usual vividness  and  permanence,  and  are,  therefore,  pe- 
culiarly liable  to  be  mistaken  for  their  prototypes.  This 
remark  applies  particularly  to  objects  of  sight  and  hear- 
ing, which  are,  in  such  cases,  termed  specters,  or  spectral 
illusions.  Yet,  even  here,  the  shadowy  character  of  ideas 
is  still  discernible.  Error  arises  chiefly  from  the  atten- 
tion being  so  concentrated  on  the  idea  that  the  difference 
between  it  and  the.  apprehension  is  overlooked,  although 
some  palpable  difference  always  exists.  Thus,  even  after 
looking  at  the  Sun,  when  the  specter  is  still  seen,  in  spite 
of  all  efforts  to  will  it  away,  the  difference  is  so  palpa- 
ble that  no  person  need  confound  it  with  seeing  the  real 
disc  of  the  Sun.  (10) 

The  presence  of  something  closely  resembling  an  ob- 
ject, is  apt  to  produce  the  same  illusion  as  disease,  espe- 
cially where  the  organs  are  placed  in  unfavorable  circum- 
stances, and  the  mind  is  affected  with  any  strong  emotion. 
A  dark  log  seen  in  a  wood  at  night,  may  lead  a  timid 
person  to  think  that  it  is  a  robber,  lying  in  wait  for  his 
victim,  the  excitement  probably  causing  an  unusually  viv- 
id idea  of  some  grim  countenance  to  arise,  and  complete 
what  the  real  object  lacks.  But,  in  all  such  cases,  we 
have  only  to  view  the  object  calmly  and  attentively,  in 
order  to  avoid  erroneous  conclusions.  Wherever  disease 
affects  the  apprehensions,  there  are  discoverable  indica- 
tions of  its  presence,  to  put  us  on  our  guard ;  and  we 


SEC.  1.]  APPREHENSIONS.  73 

have  only  to  attend  carefully  to  all  that  is  actually  dis- 
cerned, in  order  to  avoid  error. 

In  some  cases,  disease  causes  objects  to  affect  us  differ- 
ently from  what  they  do  in  health.  But  such  changes  do 
not  in  the  least  affect  the  reality  of  the  apprehensions : 
they  only  warn  us  to  be  cautious  in  assuming  that  ob- 
jects are  what  they  appear  to  a  diseased  organ. 

To  mistake  an  apprehension  for  an  idea,  is  a  very  rnro 
occurrence,  because  the  characteristics  of  the  former  arc 
so  palpable  that  a  very  slight  degree  of  attention  suffices 
to  identify  it.  Hence  such  a  mistake  hardly  ever  occurs, 
except  where  the  thing  apprehended  is  so  strange  or  un- 
expected as  to  astound  us,  and  consequently  withdraw 
the  attention  from  the  actual  apprehension. 

When  we  have  observed  the  characteristic  marks  of 
an  apprehension,  any  mistake  regarding  its  reality  is  im- 
possible. When  we  feel  heat  or  cold,  for  example,  or  per- 
ceive certain  colors,  the  only  question  is,  whether  they  are 
not  mere  ideas,  as  the  reality  of  the  comprehension  ad- 
mits of  no  doubt.  What  causes  it,  is  quite  another  mat- 
ter, which  should  not  be  confounded  with  its  reality.  In 
order  to  test  this,  we  have  only  to  ascertain  whether  it 
possesses  those  peculiarities  which  distinguish  it  from 
ideas.  If  it  does,  its  reality  is  certain.  If  a  man  should 
seriously  offer  to  prove  to  us  that  we  felt  cold,  saAV 
certain  colors,  or  heard  certain  sounds,  when  we  ac- 
tually did  so,  we  should  justly  consider  him  deranged ; 
and  such  an  offer  would  be  still  more  ridiculous  if  we  did 
not  so  apprehend.  It  is  self-evident  that  apprehensions 
cannot  exist  without  being  real,  that  they  exist  only  be- 
cause they  are  apprehended,  that  they  are  precisely  as 
they  are  apprehended,  and  that,' unless  they  were  appre- 
hended, they  could  not  possibly  exist;  Their  being  ap- 
prehended, therefore,  necessarily  implies  their  reality,  just 
as  they  are  apprehended. 

Apprehensions  should  not  be  confounded  with  their 
causes,  which  are  widely  different  things,  but  with  which 
they  are  very  liable  to  be  confounded.  Apprehensions 
are  purely  mental  phenomena,  while  their  causes  are  ex- 
ternal things  totally  different  from  the  mind,  and  some- 
times at  a  great  distance.  Two  persons  may  be  very 
differently  affected  by  the  same  objects;  yet  this  does 
not  render  the  apprehension  of  each  a  whit  the  less  real. 
When  we  see  and  smell  a  rose,  the  colors  we  perceive 

D 


74     ACQUIRING  CONTINGENT  KNOWLEDGE.    [CHAP.  III. 

exist  only  because  we  perceive  them,  just  as  much  as  the 
odor  we  feel  exists  because  .we  smell  it.  The  flower  has 
nothing  either  in  it  or  on  it  like  the  colors  we  see,  any 
more  than  it  contains  something  like  the  odor  which  we 
feel,  but  only  something  widely  different,  which  causes 
these  apprehensions. 

In  regard  to  the  inferences  deducible  from  apprehen- 
sions, we  are  liable  to  err,  as  in  the  case  of  other  infer- 
ences ;  and  this  is  the  real  source  of  most  of  the  errors 
commonly  attributed  to  the  senses.  When  a  person 
touches  a  bullet,  with  the  points  of  his  fingers  crossed, 
he  thinks  there  are  two ;  yet  he  does  not  actually  per- 
ceive two.  His  apprehensions,  however,  partly  resemble 
what  he  generally  perceives  when  there  are  two;  and 
hence  he  hastily  draws  an  erroneous  inference.  So,  when 
we  first  see  the  Sun  in  the  east,  and  gradually  more  to 
the  west,  we  are  apt  to  assume  erroneously  that  we  see 
it  moving  westward,  whereas  a  little  consideration  will 
show  that  we  see  no  such  thing.  All  that  we  observe 
is,  a  change  in  the  relative  position  of  the  sun  and  the 
direction  of  sight,  while  we  hold  the  same  apparent  posi- 
tion. Now  there  is  such  a  change:  but  whether  it  is 
owing  to  a  motion  of  the  latter  or  of  the  former,  or  of 
both,  the  senses  say  not.  Nor  do  we  see  the  road  run- 
ning away,  when  Ave  look  out  behind  a  vehicle  in  which 
we  are  traveling.  We  can  see  things  only  as  they  ap- 
parently are  at  the  present  moment ;  and,  therefore,  we 
cannot  possibly  see  a  body  moving.  We  think  we  do 
so,  only  because  we  confound  our  inferences  with  our 
perceptions. 

In  all  such  cases  as  the  preceding,  the  error  has  gener- 
ally been  attributed  to  the  senses,  whereas  they  are  er- 
rors of  reasoning,  and  the  senses  indicate  nothing  but 
what  is  strictly  true.  To  guard  against  such  errors, 
therefore,  all  we  require  to  do,  is,  to  test  the  validity  of 
the  reasoning,  as  in  other  cases.  When  this  has  been 
done  with  the  requisite  degree  of  care,  the  certainty  of 
the  inference  is  established,  beyond  the  possibility  of  a 
rational  doubt. 

The  validity  of  inferences  from  apprehensions  can  be 
tested,  not  only  by  a  strict  examination  of  the  reasoning 
processes,  but  also  by  comparing  our  conclusions  with 
those  of  other  persons,  or  those  of  one  sense  with  the 
evidence  of  another.  Thus,  if  I  see  the  likeness  of  a  de- 


SEC.  2.]          PRIMARY  MENTAL  PROCESSES.  75 

ceased  person,  I  may  feel  with  my  hand,  or  a  cane,  wheth- 
er there  is  really  any  such  being  where  he  appears  ;  or  I 
may  inquire  of  others  whether  they  see  anything  there ; 
and  if  I  suspect  that  I  hear  a  sound,  without  any  impres- 
sion being  made  on  the  ear,  I  may  look  whether  there  is 
any  sounding  body  within  hearing,  or  ask  others  wheth- 
er they  heard  such  a  sound.  We  can  also,  in  many  in- 
stances, indirectly  determine  the  truth,  without  any  such 
appeals  as  the  preceding.  Thus,  if  I  suspect  that  I  see 
single 'objects  double,  I  have  only  to  look  at  my  right 
hand,  or  some  other  object  which  I  know  to  be  single, 
and  observe  whether  I  see  it  double  or  single. 

§  2.  PRIMARY  MENTAL  PROCESSES  BY  WHICH  CONTINGENT  KNOWL- 
EDGE MAY  BE  ACQUIRED. — Our  own  Existence  implied  in  our  Ap- 
prehensions.— These  often  independent  of  our  Volitions.— Neces- 
sary inference. — Changes  caused  by  our  Volitions. — How  we  distin- 
guish Ourselves  from  other  beings  —  learn  the  condition  of  our 
organs,  through  one  sense — and  move  them  at  pleasure. — How  we 
know  the  existence  of  other  Substantial  Beings. — Why  mankind 
attribute  the  phenomena  of  Apprehension  to  their  true  causes,  not- 
withstanding certain  errors. — What  these  are. — Extrinsic  and  In- 
trinsic Properties. — Principal  kinds  of  each,  and  how  learned. — 
Particular  means  of  learning  Intrinsic  Properties,  from  simple  Ob- 
servation.— Causes  of  the  Contingent  Properties  of  Inanimate  Sub- 
stances, and  of  Living  Bein'gs. — Connection  of  Apparent  and  Real 
Similarity. — Means  of  enlarging  our  personal  Experience. — Acqui- 
sition of  Language. 

My  apprehensions,  of  which  I  am  immediately  con- 
scious, necessarily  imply  the  existence  of  the  substantial, 
living  and  thinking  self;  for  I  know  intuitively  that 
thought  cannot  exist  in  a  nonentity,  and  that  a  being 
Avhich  thinks,  must  be  substantial,  living  and  thinking. 
When  I  view  the  sky  or  the  fields,  for  example,  I  am  im- 
mediately conscious  of  certain  apprehensions  which,  I 
know  intuitively,  cannot  be  discerned  by  a  nonentity, 
and  must  exist  in  a  substantial  being.  This  being  must 
be  capable  of  discerning  the  phenomena,  or,  in  other 
words,  he  must  be  a  living  being ;  else  he  could  not  dis- 
cern them.  A  dead  rock  or  piece  of  wood  cannot  dis- 
cern anything,  and  much  less  can  a  nonentity,  or  mere 
vacuity. 

Some  apprehensions  are  pleasant,  and  others  painful. 
The  former  excite  a  desire  that  they  should  continue; 
and  the  latter  excite  aversion,  or  a  desire  that  they  should 
cease.  Yet  the  actual  result  is  often  otherwise :  the 


76    ACQUIRING  CONTINGENT  KNOWLEDGE.   [CHAP.  in. 

former  cease,  and  the  latter  continue,  in  spite  of  my  voli- 
tions to  the  contrary.  If  a  person  passes  me  with  a  bas- 
ket of  fragrant  flowers,  the  agreeable  odor  ceases  when 
they  are  removed,  however  much  I  may  will  that  it  should 
continue ;  and  when  a  wasp  stings  my  hand,  the  pain 
does  not  cease  for  some  time,  although  I  strongly  will 
that  it  should.  In  many  cases,  .changes  occur  while  I 
have  no  desire  or  volition  either  way,  as  when  I  view  a 
flowing  stream,  while  I  am  quite  indifferent  whether  it 
flow  or  not.  Thus  I  learn  that  many  of  the  changes 
which  occur  around  me,  are  wholly  independent  of  my 
wishes  or  volitions. 

Every  change  which  I  experience,  must  originate  ei- 
ther from  my  own  volitions,  or  from  spontaneous  mo- 
tions of  my  parts,  or  from  one  or  more  other  beings ; 
and,  as  no  being  destitute  of  thoilght  can  originate  mo- 
tion, my  parts  will  not  move  spontaneously,  unless  they 
are  the  seat  of  distinct  thoughts.  In  that  case  they  would 
cease  to  be  a  part  of  myself,  since  a  being  possessing  dis- 
tinct thoughts  and  power  of  motion,  must  evidently  be  a 
distinct  being,  and  form  n.o  part  of  myself.  All  those 
changes,  therefore,  which  I  experience,  independently  of 
my  volitions,  are  produced  by  one  or  more  beings  dis- 
tinct from  myself. 

On  the  other  hand,  many  changes  are  produced  by  my 
own  volitions,  including  all  my  words  and  voluntary  ac- 
tions. This  appears  conclusively  from  their  uniformly 
following  and  conforming  to  all  my  volitions.  For  the 
phenomena  exhibit  so  much  uniformity  and  regularity,  in 
an  endless  variety  of  circumstances,  that  casual  or  chance 
agencies  are  wholly  excluded,  and  no  other  being  would 
so  obsequiously  anticipate  all  my  wishes,  and  expend 
such  an  immense  amount  of  skill  and  labor  in  deluding 
me,  to  no  purpose,  as  he  could  have  no  possible  motive 
for  the  deception.  Moreover,  the  supposed  being  would 
possess  contradictory  attributes.  He  would  be  benevo- 
lent, since  he  often  operated  to  procure  me  enjoyment — 
and  he  would  be  malevolent,  since  he  often  deluded  me, 
and  led  me  into  severe  and  lasting  pain,  by  gratifying  my 
wishes.  The  being  could  not  design  to  improve  me  by 
discipline,  as  I  should  be  only  a  passive  recipient  of  what- 
ever he  chose  to  bestow  or  inflict. 

Those  changes  cannot  be  caused,  without  any  external 
reality,  by  different  beings,  some  benevolent  and  so'.ne 


SEC.  2.]          PRIMARY  MENTAL  PROCESSES.  77 

malicious :  for  ejther  the  stronger  would  exclude  the 
weaker  from  all  control,  or,  if  they  were  equally  strong, 
the  one  under  whose  power  I  fell,  would  retain  his  su- 
premacy. An  indifferent  being  would  evidently  not  in- 
terfere with  me  at  all.  (11) 

I  learn  the  limits  of  my  own  person  by  observing  that 
its  parts  are  all  firmly  connected,  and  that  they  uniform- 
ly and  immediately  obey  my  volitions,  without  any  ap- 
prehensible command  or  request,  which  no  other  object 
does.  If  I  will  to  move  my  foot,  under  the  belief  that  it 
exists,  and  is  connected  with  me,  I  notice  a  change  in  the 
position  of  the  colors,  and  feel  some  new  sensations,  as  if 
I  had  actually  moved  it :  but  if  I  will  similarly  regarding 
any  distinct  object  around  me,  there  is  no  such  change. 

So,  if  I  will  to  move  from  the  chair  on  which  I  sit  to 
another,  my  limbs  all  move  in  harmony  to  my  new  posi- 
tion, while  my  former  seat  remains  precisely  as  it  was. 
Those  objects  are  evidently  parts  of  myself  which  are  in- 
separably connected  with  me,  and  immediately  obey  my 
volitions ;  and  all  other  objects  are  not  parts  of  myself, 
as  they  are  unconnected  with  me,  and  do  not  move  uni- 
formly and  directly  in  accordance  with  my  volitions,  save 
when  they  are  attached  to  me  by  artificial  means,  or  in 
immediate  connection  with  some  of  my  parts. 

I  learn  the  position  and  other  peculiarities  of  my  or- 
gans, at  any  instant,  through  a  particular  sense,  by  first 
noting  the  perceptions  and  sensations  which  I  experience 
when  some  other  sense  informs  me  of  those  peculiarities. 
Thus,  I  know  the  position  of  my  right  hand,  at  any  in- 
stant, independently  of  sight  or  touch,  by  first  marking 
the  apprehensions  discerned  when  I  either  see  its  position 
or  feel  it  with  my  left  hand ;  and  these  apprehensions 
afterwards  inform  me  of  its  condition,  without  any  aid 
from  other  senses,  as  I  justly  infer  that  they  are  the  same 
as  when  my  apprehensions  regarding  it  were  precisely 
similar. 

When  I  know  the  condition  of  an  organ  of  motion,  a 
little  experience  enables  me  to  move  it  at  pleasure,  as  I 
know  the  very  tiling  to  be  willed,  in  order  to  effect  the 
required  motion. 

The  various  changes  I  experience,  which  do  not  orig- 
inate with  myself,  must  result  either  from  one  being  or 
from  several.  The  former  supposition  is  known  to  be 
absurd,  just  as  I  know  that  my  actions  are  caused  by  my 


78     ACQUIRING  CONTINGENT  KNOWLEDGE.    [CHAP.  III. 

volitions.  Hence  those  phenomena  must  be  owing  to 
several  beings ;  and  they  may  produce  them  either  by 
communicating  various  motions  to  me,  by  means  of  in- 
tervening substances,  or  by  coming  into  direct  contact 
with  me.  They  can  affect  me  only  in  one  or  other  of 
these  ways :  for  it  is  self-evident  that  they  can  cause  no 
change  in  me  without  actual  contact  or  a  medium.  I 
cannot  evidently  be  immediately  conscious  of  the  pres- 
ence of  any  external  object,  unless  it  is  directly  in  con- 
tact with  my  living  self.  The  immediate  causes  of  those 
phenomena  may  be  very  different  from  the  ultimate,  or 
even  the  remoter,  causes. 

The  various  phenomena  presented  by  the  substances 
around  me,  imply  that  some  of  them  possess  thought, 
like  myself,  and  others  do  not.  For  the  former  exhibit 
changes  similar  to  those  which  precede  and  follow  my 
own  volitions,  while  the  latter  are  either  uniformly  inert, 
and  never  act  or  move  save  when  they  are  affected  by 
some  other  substance,  or  they  do  so  only  in  one  particu- 
lar way,  thus  indicating  that  they  are  always  passive. 
The  supposition  of  the  former's  motions  being  caused  by 
substances  distinct  from  themselves,  involves  the  absurd- 
ity already  pointed  out ;  and  it  implies  the  further  ab- 
surdity that  these  beings  employ  immense  pains  and 
skill  to  delude  me  into  the  erroneous  belief  that  there  are 
other  beings  like  myself,  without  any  motive  for  their 
doing  so. 

The  only  admissible  inference,  therefore,  is,  that  I  am 
surrounded  by  a  great  variety  of  real  beings,  some  ani- 
mate and  some  not,  the  former  of  which  feel,  will  and  act 
as  I  do  myself.  Each  class  presents  numerous  kinds, 
which  differ  widely  ;  yet  the  essential  distinction  between 
the  two  is  generally  well  marked  throughout.  There  is 
one  species  of  the  former  to  which  I  evidently  belong,  as 
it  is  precisely  like  myself,  while  all  the  rest  differ,  some 
more  and  some  less. 

On  applying  the  tests  furnished  by  my  various  senses, 
I  am  only  confirmed  in  those  conclusions.  If  a  friend  is 
speaking  to  me,  and  walking  near  me,  with  a  fragrant 
flower  in  his  hand,  I  hear  his  voice  and  the  sound  of  his 
footsteps,  see  his  person  and  movements,  and  smell  the 
odor  of  the  flower,  while  he  answers  my  questions  or  re- 
marks ;  and  if  I  lay  my  hand  on  his  head,  I  feel  it,  as  soon 
as  I  see  the  colors  come  in  contact.  At  the  same  time 


SEC.  2.  |          PRIMARY  MENTAL  PROCESSES.  79 

the  variations  in  the  tones  of  his  voice,  his  footsteps  and 
motions,  and  the  odor  of  the  flower,  correspond  to  those 
in  his  appearance,  as  if  he  were  at  different  distances  and 
in  different  positions.  Sometimes  the  apprehensions  are 
multiplied  by  the  presence  of  many  persons  at  the  same 
time. 

These  phenomena  admit  of  no  rational  explanation  ex- 
cept that  they  are  caused  by  those  things  to  which  they 
are  usually  attributed:  for  the  few  other  possible  ex- 
planations involve  gross  absurdities.  The  phenomena 
exhibit  a  degree  of  regularity  and  uniformity  which 
wholly  excludes  the  supposition  of  their  being  casual  or 
accidental,  and  that  of  another  being  designedly  produc- 
ing them,  labors  under  the  difficulties  already  pointed 
out.  Hence  the  only  obvious  supposition  regarding  the 
causes  of  apprehensions,  is  the  true  one.  It  not  only  ac- 
counts for  them,  with  perfect  precision,,  but  every  other 
supposition  involves  impossibilities. 

Mankind  generally  attribute  the  phenomena  of  appre- 
hension to  their  true  causes,  since  these  alone  are  obvi- 
ous ;  but  this  is  done,  from  early  infancy,  with  such  ease 
and  rapidity  that  they  overlook  the  process  of  inference, 
and  take  that  to  be  an  immediate  discernment  which  is, 
in  reality,  an  inference.  This  error  causes  difficulties 
when  the  subject  is  attempted  to  be  investigated,  be- 
cause those  inferences  are  sometimes  false,  which  the  real 
phenomena  of  consciousness  never  are.  Men  also  fall 
into  the  further  error  of  overlooking  the  other  possible 
explanations  that  may  be  given  of  the  phenomena ;  but 
this  is  of  no  consequence,  since  a  careful  analysis  shows 
that  these  all  involve  absurdities. 

The  contingent  properties  of  substances,  or  those 
which  are  not  self-evident,  are  of  two  kinds,  extrinsic 
and  intrinsic.  The  former  consist  of  those  which  are 
known  only  by  their  causing  in  us  certain  apprehensions 
essentially  different  from  anything  inherent  in  the  sub- 
stances, and  apparently  dependent  solely  on  the  form 
and  arrangement  of  their  molecules  or  atoms.  The  prin- 
cipal of  these  are,  color,  and  those  which  produce  the 
apprehensions  of  smell,  taste  and  sound.  These  are  made 
known  to  us  directly,  through  the  'proper  organs.  The 
color  of  an  object  is  learned  by  the  eye — the  smell,  by 
the  nose — the  taste,  by  the  mouth — and  the  sounds  which 
they  give  forth,  by  the  ear. 


80     ACQUIRING  CONTINGENT  KNOWLEDGE.    [CHAP.  III. 

The  intrinsic  properties  of  substances  consist  of  those 
which  are  inherent  in  them,  and  are  not  dependent  mere- 
ly on  their  molecular  structure  and  discovered  solely  by 
certain  apprehensions  produced  in  us  in  consequence  of 
that  structure.  The  principal  of  these  are,  particular 
form  or  shape,  size,  position,  weight  or  gravity,  inertia, 
mechanical  texture,  and  the  various  qualities  dependent 
on  it,  temperature,  electric  and  chemical  properties,  life, 
and  the  various  properties  connected  with  it. 

We  must  distinguish  the  particular  and  actual  quali- 
ties of  a  substance  from  the  general  properties  of  the 
same  kind  known  by  Intuition.  We  know  intuitively 
that  every  substance  must  have  some  form,  size  and  posi- 
tion :  but  the  actual  form,  size  and  position  of  a  substance 
are  contingencies  which  we  must  learn  from  experience, 
and  which  cannot  be  ascertained  by  Intuition.  This  class 
of  properties  is  mostly  inferred  from  phenomena,  by  va- 
rious processes,  of  which  the  following  are  the  principal, 
belonging  to  the  subject  of  this  section. 

The  eye  perceives  nothing  but  various  expanded  col- 
ors, which  frequently  change  their  apparent  forms  and 
positions;  and  we  learn  the  actual  forms,  distances  and 
positions  of  the  colored  substances  by  drawing  inferences 
regarding  the  causes  of  the  apprehensions  which  they 
produce. 

If  we  feel  with  our  fingers  any  object,  such  as  a  book, 
table  or  chair,  and  view  H  in  different  positions,  we  find 
that  the  outline  of  the  colors  presented  to  the  eye  corre- 
sponds exactly  to  the  outline  of  the  real  form,  as  determ- 
ined by  the  touch.  The  time  which  the  fingers  take  to 
move  over  its  different  parts  corresponds  to  their  appar- 
ent size,  as  exhibited  to  the  eye.  The  apparent  form  is 
such  as  would  arise  from  the  rays  of  light  passing  in 
straight  lines  from  every  part  of  the  object  to  the  eye ; 
and  as  this,  in  all  ordinary  circumstances,  happens  uni- 
formly, we  learn  that  these  rays  move  in  straight  lines. 

We  also  notice  that  the  shades  of  color  vary  accord- 
ing to  the  particular  form  of  that  part  of  the  object  which 
is  in  sight.  We  readily  distinguish  a  ball  from  a  flat  disc 
by  observing  its  darker  hue  towards  the  edges,  while  the 
latter  exhibits  no  such  difference ;  and  a  little  experience 
renders  us  familiar  with  the  peculiarities  and  causes  of 
the  variations  in  the  shades  of  color.  Thus  we  learn  to 
determine  form,  with  the  utmost  rapidity,  from  the  visi- 


SEC.  2.]          PRIMARY  MENTAL  PROCESSES.  81 

ble  outline  and  shading  alone,  without  any  application 
of  touch. 

Painted  imitations  may  sometimes  deceive  us ;  and  the 
hues  of  distant  objects  are  so  indistinct  that  we  are  apt 
to  draw  erroneous  inferences  regarding  their  forms.  But 
cases  of  this  kind  do  not  aflect  the  accuracy  of  our  con- 
clusions regarding  ordinary  objects,  within  moderate  dis- 
tances ;  and  even  there,  we  have  generally  some  reliable 
means  of  ascertaining  the  true  form,  without  the  aid  of 
touch.  A  painting  may  often  be  distinguished  from  a 
solid  by  its  not  possessing  the  vividness  of  nature,  and 
its  not  changing  as  we  vary  the  position  of  the*  eye.  We 
also  frequently  know  that  the  circumstances  are  such  as 
to  exclude  the  supposition  of  any  painting  being  visible. 
So  the  different  appearances  of  the  dark  spots  on  the  sur- 
face of  the  Sun,  as  it  revolves  on  its  axis,  show  us,  not- 
withstanding its  great  distance,  that  it  is  a  solid  body. 

We  can  form  an  estimate  of  the  size  of  a  body  which 
is  quite  close  to  us,  by  comparing  it  with  that  of  our  hand 
or  foot :  and  when  it  is  within  a  moderate  distance,  we 
form  a  judgement  from  its  apparent  size,  the  degree  of  dis- 
tinctness in  its  color  and  outlines,  the  number  and  mag- 
nitude of  intervening  objects,  and  comparing  it  with  a 
body  near  it  whose  dimensions  are  known.  A  little  ex- 
perience shows  us  the  modes  in  which  the  appearance 
of  an  object  varies  with  its  position.  But  such  methods 
furnish  only  approximations  in  any  case ;  and  where  the 
body  is  very  remote,  as  the  Sun  or  Moon,  they  wholly 
fail.  The  exact  dimensions  of  objects  can  generally  be 
ascertained  only  by  actual  measurements  and  calcula- 
tions. 

The  distance  of  an  object  cannot  possibly  be  appre- 
hended directly,  since  space  is  invisible ;  and  it  is  esti- 
mated in  the  same  way  that  we  judge  of  its  size.  In- 
deed the  two  properties  are  so  related  that  a  knowledge 
of  one  assists  us  in  determining  the  other.  We  either 
form  an  estimate  of  its  distance  from  its  appearance,  and 
then  judge  of  its  size,  on  the  assumption  that  it  is  at  such 
a  distance,  or,  if  we  know  its  actual  size,  we  can  form  an 
estimate  of  its  distance  from  its  appearance. 

Another  criterion,  which  may  be  frequently  applied  to 
ascertain  the  distance  of  an  object,  is,  the  nature  of  the 
sounds  which  proceed  from  it :  for  this  varies  with  the 
distance,  winch  can  consequently  be  determined  approx- 

D  2 


82     ACQUIRING  CONTINGENT  KNOWLEDGE.   [CHAP.  III. 

imately  from  noting  the  character  of  the  sound,  as  it 
strikes  the  ear.  The  differences  in  the  sounds  are  learn- 
ed by  noting  their  character  when  the  distance  is  known 
by  some  other  means. 

The  direction  of  a  visible  object  may  be  ascertained  by 
observing  its  bearing,  compared  with  the  line  whence  the 
direction  is  reckoned.  Sometimes  the  direction  of  an  in- 
visible object  is  determined  by  observing  the  quality  of 
sounds  proceeding  from  it,  as  these  affect  the  ear  differ- 
ently according  to  the  directions  in  which  the  sonorous 
undulations  are  moving ;  and  we  learn  the  various  mod- 
ifications by  observing  the  character  of  the  sound  where 
the  direction  is  known  by  sight,  touch,  or  any  other 
means.  The  form  of  the  ear  is  such  that  sonorous  un- 
dulations affect  it  variously,  according  to  the  directions 
in  which  they  move. 

The  direction  of  one  distant  object  from  another  may 
be  roughly  estimated  by  determining  the  distance  of 
each,  and  then  observing  the  angle  which  they  form  with 
each  other,  measured  from  the  eye  of  the  observer. 

In  a  void  we  cannot  distinguish  one  direction  from  an- 
other ;  and  hence  the  direction  of  an  object  can  be  de- 
termined only  by  observing  its  position  in  relation  to 
three  or  more  fixed  points.  While,  therefore,  this  posi- 
tion continues  apparently  the  same,  a  change  of  direction 
is  imperceptible,  as  when  we  sit  in  the  cabin  of  a  vessel 
which  changes  its  direction,  we  are  not  sensible  of  the 
change,  because  everything  we  see  around  us  preserves 
the  same  relative  position.  Where  there  is  an  evident 
change  of  position,  it.  is  frequently  difficult  to  ascertain 
which  object  has  moved.  When  I  look  over  the  side  of 
a  ship,  and  see  the  water  apparently  moving  astern,  I 
cannot  directly  say  whether  the  vessel  is  moving  against 
the  flood,  or  whether  she  is  at  anchor,  with  the  tide  or 
current  flowing  past.  I  can  ascertain  the  real  fact  only 
by  looking  at  the  shore  or  some  fixed  object. 

The  same  remark  applies  to  two  railway  trains  which 
cross  each  other :  and  the  apparent  motions  of  the  heav- 
enly bodies  furnish  another  instance,  which  differs  from 
these,  however,  in  there  being  no  fixed  object  to  remove 
the  difficulty.  We  are*apt  to  think  that  the  bodies  move, 
and  that  the  Earth  is  at  rest,  because  they  are  apparent- 
ly much  smaller  than  the  latter,  and  every  object  around 
us  preserves  the  same  relative  position.  Our  persons 


SEC.  2.]          PRIMARY  MENTAL  PROCESSES.  83 

appear  to  stand  in  the  same  vertical  direction  through- 
out the  day ;  and  if  we  turn  towards  the  pole-star,  our 
two  hands  seem  to  point  always  in  the  same  directions. 

When  we  know  the  distance  and  direction  of  an  ob- 
ject, we  know  its  position  in  space,  in  relation  to  our- 
selves :  but  we  cannot  determine  absolute  position,  be- 
cause we  cannot  distinguish  one  part  of  space  from  an- 
other, and  all  objects  around  us  may  possibly  be  in  mo- 
tion, and  yet  constantly  preserve  the  same  relative  posi- 
tion. 

The  weight  of  a  substance  may  frequently  be  known 
approximately  by  observing  its  momentum  or  moving 
force,  to  which  it  is  always  proportional,  for  a  certain 
velocity ;  and,  in  all  cases,  it  may  be  estimated  by  ob- 
serving the  effects  which  the  substance  has  produced  by 
its  motions. 

The  inertia  of  a  substance  is  its  tendency  to  continue 
in  its  present  state  of  rest  or  motion,  and  its  requiring 
the  application  of  force  to  produce  any  change  in  that 
state.  The  general  property  is  learned  by  simple  ob- 
servation ;  and  accurate  measurements  show  that  it  is 
exactly  proportional  to  the  weight  of  the  body.  Hence 
the  amount  of  the  former  is  always  known  from  that  of 
the  latter. 

The  mechanical  texture  of  a  substance  is  frequently 
learned  from  simple  observation.  Thus  we  see  that  ice 
is  solid,  water  fluid,  and  steam  gaseous,  and  that  iron  is 
tough  and  rigid,  glass  hard  and  brittle,  and  moist  clay, 
soft  and  plastic. 

The  temperature  of  several  substances  may  frequently 
be  loosely  determined  from  our  sensations,  or  observing 
their  heating  or  cooling  effects  on  other  substances,  and 
sometimes  from  their  very  appearance.  Thus,  we  know 
that  ice  is  generally  colder,  and  steam  warmer  than  li- 
quid water. 

Some  of  the  chemical  and  electric  properties  of  sub- 
stances may  be  learned  by  observation  ;  but  most  of  them 
are  discovered  only  by  means  of  experiments. 

The  peculiar  characteristics  of  living  beings  may  be 
learned  by  observing  their  modes  of  acting.  Life  is  dis- 
tinguished by  the  power  of  originating  or  stopping  mo- 
tion, independently  of  external  application  or  mere  iner- 
tia ;  and  the  differences  between  the  various  classes  of 
animals  are  learned  from  the  modes  in  which  they  act, 


84    ACQUIRING  CONTINGENT  KNOWLEDGE.    [CHAP.  III. 

or  are  affected  by  the  various  circumstances  in  which 
they  are  found.  Thus,  some  exhibit  cunning,  and  others, 
simplicity ;  some  are  gentle,  and  others,  fierce ;  some  are 
strong,  and  others,  weak,  and  so  forth. 

We  know  the  nature  of  our  own  comprehensions  by 
direct  consciousness ;  and  we  infer  that  other  beings  of 
our  own  species  discern  as  we  do,  when  they  are  placed 
in  the  same  circumstances  with  us,  and  exhibit  the  same 
appearances  which  we  present  when  so  situated.  We 
reason  upon  the  principle  that  the  results  are  the  same, 
where  the  determining  conditions  are  the  same. 

The  causes  of  the  contingent  properties  of  inanimate 
substances  must  be  owing  to  the  form  and  arrangement 
of  their  atoms,  and  their  being  variously  affected  by  oth- 
er substances.  But  we  can  seldom  trace  a  particular 
property  to  any  of  these  causes.  We  cannot  show  why 
gold  reflects  only  the  yellow,  and  grass  the  green  rays, 
or  why  nitric  acid  corrodes  iron  and  silver,  while  it  does 
not  affect  gold  or  platinum. 

In  order  to  trace  the  causes  of  those  properties,  we 
should  require  to  know  the  atomical  constitution  of  mat- 
ter :  and  this  we  can  never  do ;  for  however  much  mi- 
croscopes may  magnify,  one  of  greater  power  might 
show  that  to  be  porous  which  formerly  appeared  to  be 
solid.  For  the  same  reason,  we  cannot  trace  any  con- 
nection between  the  different  properties  of  substances, 
although  such  a  connection  may  possibly  exist.  We 
cannot  determine  the  tenacity  of  a  metal  from  its  color, 
nor  its  fusibility  from  its  specific  gravity. 

With  regard  to  the  properties  of  living  beings,  we 
are,  if  possible,  still  more  unable  to  trace  them  to  their 
causes,  farther  than  we  can  do  by  pure  Intuition.  The 
causes  of  the  origin  and  ultimate  conditions  of  life,  seem 
to  baffle  all  human  efforts  to  trace  them.  We  readily 
learn  that  certain  conditions  are  requisite  to  life,  and  that 
death  ensues  when  they  are  violated :  but  why  this  is  so, 
nobody  can  tell.  A  small  quantity  of  an  apparently 
harmless  substance  causes  speedy  death,  while  a  much 
larger  quantity  of  another  substance,  apparently  much 
more  injurious,  fails  to  do  so.  All  that  we  can  here  ef- 
fect, is,  to  establish  the  existence  of  certain  intermediate 
conditions  or  causes;  and  even  this  is  done  chiefly  by 
indirect  means. 

With  regard  to  the  question  whether  substances  ap- 


SEC.  2.]          PRIMARY  MENTAL  PROCESSES.  85 

parent! y  quite  similar  are  so  in  reality,  we  justly  argue 
that  they  must  generally  be  so;  otherwise  some  of  their 
discoverable  attributes  would  differ.  Diamond  and 
quartz  are  frequently  similar  in  touch  and  appearance ; 
but  chemical  processes  soon  show  that  they  are  totally 
different  in-  composition :  and,  by  passing  polarized  light 
through  them,  we  may  discover  some  differences  in  the 
texture  even  of  two  diamonds.  Nor  can  we  certainly 
say  that  there  may  not  be  other  differences  which  we 
cannot  detect ;  yet  there  must  be  a  general  similarity  in 
the  structure  of  all  diamonds ;  else  they  could  not  pos- 
sess so  many  common  properties  as  they  do.  The  same 
remark  applies  to  all  similar  cases :  for  where  all  the  ef- 
fects are  alike,  the  causes  must  be  alike ;  otherwise  there 
would  be  effects  without  any  adequate  causes. 

Our  personal  comprehensions  necessarily  furnish  all 
the  primary  elements  of  our  contingent  knowledge :  but 
we  avail  ourselves  of  the  observations,  reasoning,  and  ex- 
perience of  others,  by  means  of  signs  of  thought.  These 
are  chiefly  spoken  and  written  language,  by  means  of 
which  the  knowledge  of  one  person  may  be  communi- 
cated to  all  his  contemporaries,  and  transmitted  to  the 
most  distant  times. 

We  first  learn  spoken  or  'oral  language  by  a  close  ob- 
servation of  the  usages  of  those  around  us.  The  child 
learns  the  names  of  the  visible  objects  around  him,  by 
hearing  them  repeatedly  applied,  where  he  knows  the 
object  designated ;  and  he  learns  the  names  of  qualities, 
by  hearing  them  expressed  by  certain  terms,  where  the 
things  meant  are  obvious.  The  significations  of  verbs 
are  acquired  by  observing  the  woods  applied  to  denote 
what  is  present  to  the  senses,  or  to  give  an  order  which 
is  immediately  executed :  and  the  significations  of  the 
less  abstract  words  belonging  to  the  other  parts  of 
speech,  are  acquired  in  the  same  way.  These  attain- 
ments amply  suffice  for  extending  his  knowledge  of  the 
subject,  by  means  of  information  derived  from  others, 
or  marking  their  usages  either  in  spoken  or  in  written 
discourse. 

A  knowledge  of  the  vernacular  enables  us  to  learn  the 
experience  of  those  around  us,  and  to  avail  ourselves  of 
their  comprehensions  as  if  they  were  our  own,  while  a 
knowledge  of  writing  places  within  our  reach  all  the 
most  important  facts  known  to  mankind. 


80    ACQUIRING  CONTINGENT  KNOWLEDGE.     [CHAP.  III. 

§  3.  PRIMARY  EXTERNAL  PROCESSES  BY  WHICH  CONTINGENT  KNOWL- 
EDGE MAY  BE  ACQUIRED. — Simple  Observation  frequently  insuffi- 
cient.— Standard  of  Weights  and  Measures. — Method  of  repeating 
and  taking  a  Mean. — "Requisite  to  render  it  satisfactory. — On  what 
assumption  based. — Its  Advantages. — Method  of  Approximation. 
— Method  of  Extension. — Sometimes  combined  with  Repetition. — 
Means  of  measuring  very  small  spaces. — Things  which  cannot  be 
accurately  measured. — Aids  of  Sight  and  Hearing.- — Various 
means  of  testing  results. — Experiments. — Of  two  kinds. — General 
objects  of  logical  Experiments. — One  often  subservient  to  several 
objects. — Where  Experiments  arc  generally-  requisite. — Relation 
of  Experiments  to  Comprehensions. — Use  of  visible  Symbols. — 
Curves. — Application  of  Symbols. — Tangible  Writing. 

The  methods  discussed  in  the  preceding  section  do 
not,  in  many  cases,  furnish  a  sufficiently  precise  and  ex- 
tensive knowledge  of  the  subject;  and,  therefore,  we  re- 
quire the  aid  of  several  external  processes.  In  observing 
quantity,  for  example,  we  can  generally  form  only  a 
rough  estimate  of  its  amount  from  simple  apprehension ; 
and  when  we  wish  to  ascertain  the  exact  amount,  we 
must  have  recourse  to  numeration,  measurements,  and 
calculations. 

If  a  man  sell  a  ilock  of  sheep,  at  so  much  a  head,  he 
can  possibly  tell,  at  a  glance,  that  there  are  more  than 
one  and  less  than  two  hundred ;  but  neither  he  nor  the 
buyer  can  tell  the  exact  number,  by  this  means.  In  order 
to  do  this,  the  sheep  must  be  counted.  This  process  must 
be  adopted  whenever  we  desire  to  ascertain  the  exact 
number  of  single  things  contained  in  an  aggregate  of  in- 
dividual objects,  exceeding  a  few :  and,  in  eifecting  it, 
direct  and  continuous  numbering  may  often  be  abridged 
by  means  of  the  processes  of  Arithmetic.  Thus,  the  pop- 
ulation of  a  town  is  ascertained  by  first  counting  that  of 
the  various  subdivisions,  and  then  adding  together  these 
items,  the  sum  of  which  is  the  total  amount.  So  we  may 
ascertain,  with  sufficient  accuracy,  the  number  of  pores 
in  the  whole  surface  of  the  body,  by  counting  the  num- 
ber within  a  square  inch,  in  different  parts,  till  we  ascer- 
tain the  average,  and  then  multiplying  this  by  the  num- 
ber of  square  inches  in  the  whole  area  of  the  skin. 

The  rules  of  Subtraction  and  Division  are  equally  serv- 
iceable, when  we  require  to  ascertain  differences  and  quo- 
tients or  aliquot  parts  :  and,  by  combinations  of  the  sim- 
ple processes,  all  ordinary  numerical  problems  can  be 
readily  solved,  from  facts  learned  by  direct  numeration 
or  countinp;. 


SEC.  3.]        PRIMARY  EXTERNAL  PROCESSES.  87 

In  oi»der  to  measure  quantity  accurately,  some  uniform 
standard  is  requisite :  and  we  are  furnished  with  it  by 
means  of  the  unvarying  time  which  the  Errth  takes  to 
perform  a  revolution  on  its  axis.  This  enables  us  to  de- 
termine the  mean  length  of  a  solar  day,  which  is  the  more 
immediate  standard  of  time.  We  have  no  direct  percep- 
tion of  the  flow  of  time;  and  hence  we  do  not  know  what 
time  is  occupied  by  a  revery  or  a  dream.  We  can,  in- 
deed, form  some  estimate  of  the  lapse  of  time  by  noting 
the  number  of  objects  of  which  we  have  thought  during 
the  interval,  or  the  amount  of  work  done,  or  the  distances 
traveled  by  us,  or  bodily  sensations,  which  indicate  a  par- 
ticular period  of  the  day  or  year,  and  so  forth.  But  such 
methods  do  not  possess  the  accuracy  required  for  many 
purposes.  In  order  to  this,  we  employ  time-keepers, 
which  are  regulated  by  the  apparent  diurnal  motions  of 
the  fixed  stars,  corresponding  to  the  real  diurnal  revolu- 
tion of  the  Earth. 

By  taking  a  pendulum  which  swings  so  many  times 
in  a  mean  solar  day,  under  specified  circumstances  of  po- 
sition, heat  and  atmospheric  pressure,  we  are  supplied 
with  a  standard  of  length,  which  serves  equally  for  meas- 
uring surfaces  and  solids.  Then,  by  taking  a  certain  solid 
measure  of  pure  water,  of  a  given  temperature,  and  un- 
der a  given  atmospheric  pressure,  we  have  a  standard  of 
weights. 

The  ordinary  modes  of  measuring  and  weighing  are 
sufficiently  accurate  for  common  purposes.  But,  in  many 
scientific  processes,  the  instruments  require  to  be  con- 
structed with  the  utmost  accuracy ;  and,  after  using 
them  with  all  practicable  exactness  and  care,  some  expe- 
dients are  still  employed  to  eliminate  errors. 
•  Accuracy  is  frequently  obtained  by  repeating  a  certain 
measurement,  with  all  possible  exactness,  and  then  taking 
the  mean  of  the  whole.  Thus  the  diameter  of  the  Earth 
has  been  determined  from  various  accurate  and  inde- 
pendent measurements,  no  two  of  which  gave  precisely 
the  same  results,  although  they  differed  by  less  than  one 
tenth  of  a  mile ;  and,  by  taking  the  mean  of  all  those 
measurements,  a  result  is  obtained  more  reliable  than 
that  deduced  from  any  single  measurement.  So  the  par- 
allax of  the  Sun  has  been  similarly  determined,  to  a  great 
degree  of  accuracy,  from  different  observations  of  the 
transits  of  Venus  over  its  disc. 


88    ACQUIRING  CONTINGENT  KNOWLEDGE.   [CHAP.  III. 

To  render  this  method  quite  satisfactory,  one  measure- 
ment must  be  as  reliable  as  another ;  for,  if  some  were 
made  carelessly  or  with  inferior  instruments,  they  should 
evidently  be  excluded  from  those  employed  in  determin- 
ing the  mean.  The  process  is  based  on  an  assumption 
which  experience  shows  to  hold  true,  and  which  the  cir- 
cumstances of  such  cases  warrant  us  in  assuming,  name- 
ly, that,  in  a  great  variety  of  measurements,  all  performed 
with  equal  care,  with  equally  good  instruments,  and  with- 
out any  peculiar  difficulties  one  way  more  than  another, 
errors  in  one  direction  are  very  nearly  compensated  by 
those  in  the  contrary  direction,  some  falling  just  as  much 
short  as  others  go  beyond  the  truth. 

This  method  may  obviate  errors  due  to  defects  of  in- 
struments, as  well  as  those  arising  from  inaccuracies  of 
observation;  and  it  sometimes  enables  the  observer  to 
eliminate  errors  due  to  defects  in  his  instrument  even 
without  any  aid  from  a  second.  Thus,  if  we  carefully 
measure  the  angular  distance  between  two  stars,  on  dif- 
ferent parts  of  a  graduated  circular  arc,  and  take  a  mean, 
we  obviate  any  small  error  arising  from  inaccuracy  of 
graduation.  So,  if  we  weigh  a  body  in  the  different 
scales  of  the  same  balance,  we  can  determine  its  actual 
weight,  although  one  arm  of  the  balance  should  be  long- 
er than  the  other.  Again,  if  we  first  balance  the  thing  to 
be  weighed  with  sand,  and  then  replace  it  with  weights, 
we  determine  its  exact  weight,  independently  of  all  the 
defects  of  the  balance,  provided  only  that  it  is  easily 
moved  by  a  very  small  weight ;  for,  as  the  circumstances 
are  the  same  in  both  cases,  the  sand  must  balance  equal 
weights. 

Approximation  is  another  method  of  aiding  apprehen- 
sion. The  quantity  sought  is  first  found  approximately 
from  observation ;  then,  by  means  of  this  result,  we  find 
another  quantity,  which  differs  less  from  perfect  accuracy, 
and  so  on,  to  any  required  degree  of  exactness.  Instan- 
ces of  this  method  are  furnished  by  the  ordinary  modes 
of  finding  the  successive  figures  of  dividends  and  roots. 

Another  method  of  aiding  apprehension  is,  to  extend 
our  observations,  so  as  to  include  many  similar  cases,  or 
such  as  are  separated  by  wide  intervals  of  time  or  space. 
Thus,  if  we  wish  to  know  whether  granite  is  of  igneous 
origin,  we  examine  the  whole  series  of  similar  rocks, 
and  notice  a  gradual  change,  through  the  serpentine  and 


SEC.  3.]        PRIMARY  EXTERNAL  PROCESSES.  89 

trap,  till  we  come  to  the  modern  lavas,  which  are  direct- 
ly known  to  be  of  igneous  origin,  whence  we  conclude 
that  granite  had  a  similar  origin.  So,  in  determining  the 
exact  length  of  the  year,  if  we  have  two  observations 
made  at  an  interval  of  a  thousand  years,  the  errors  of  ob- 
servation will  be  so  distributed  that  the  result  will  vary 
from  the  average  length  of  the  year,  during  the  interval, 
only  by  the  thousandth  part  of  their  sum,  whereas,  if  the 
two  observations  were  made  at  an  interval  of  one  year, 
the  result  would  vary  from  the  truth  by  the  whole 
amount  of  those  errors. 

Sometimes  the  method  of  extension  may  be  combined 
with  that  of  repetition,  so  as  to  secure  the  advantages  of 
both.  Thus,  in  measuring  angular  spaces  with  the  re- 
flecting circle,  the  angle  is  repeatedly  measured  in  such 
a  manner  that  the  error  arising  from  defects  of  gradua- 
tion is  constant,  while  the  final  measurement  is  the  result 
of  all,  and  secured  against  errors  of  observation  as  in  the 
method  of  simple  repetition ;  and  as  that  of  graduation 
is  equally  distributed  through  all  the  measurements,  it 
may  be  made,  by  means  of  the  extension,  as  small  as 
the  observer  pleases. 

Very  small  spaces  are  generally  measured  by  means 
of  such  contrivances  as  a  vernier  and  a  micrometer.  But 
the  same  purpose  is  sometimes  eifected  by  particular  art- 
ifices. Thus,  the  diameter  of  a  very  slender  thread  or 
wire  may  be  determined  by  laying  ply  beside  ply,  till 
they  exactly  cover  some  small  known  space,  as  the  six- 
teenth part  of  an  inch  ;  and  if  we  find  it  takes  thirty  of 
them  to  do  so,  we  know  that  their  diameter  is  the  four 
hundred  and  eightieth  part  of  an  inch. 

Many  things  hardly  admit  of  any  greater  accuracy  of 
measurement  than  simple  observation  affords,  such  as  the 
intensity  of  a  color,  roughness  and  smoothness.  With 
respect  to  all  feelings,  whether  sensations  or  emotions, 
they  evidently  admit  of  no  measurement.  But,  in  all 
such  cases,  Comprehension  enables  us  to  determine  the 
greater  from  the  less  within  narrow  limits ;  and  this  is 
all  that  we  require,  in  such  cases,  for  practical  purposes. 
Thus,  although  we  cannot  ascertain  that  one  green  hue 
is  twice  or  thrice  as  deep  as  another,  yet  we  can  distin- 

fuish  the  various  shades,  with  great  accuracy.     So,  we 
now  that  our  sensation  of  pain  is  much  stronger  in  the 
case  of  a  severe  burn,  than  in  that  of  a  slight  abrasion  of 
the  skin. 


90    ACQUIRING  CONTINGENT  KNOWLEDGE.   [CHAP.  III. 

Sight  and  heaving,  the  two  most  prolific  sources  of  ap- 
prehensional  knowledge,  are  directly  assisted  by  instru- 
ments. The  speaking  trumpet,  by  concentrating  the  aerial 
undulations,  and  the  hearing  or  ear  trumpet,  by  collecting 
them,  enables  us  to  hear  distinctly  sounds  otherwise  in- 
audible :  and  the  simple  device  of  changing  the  direction 
of  the  rays  of  light,  by  means  of  some  refracting  or  re- 
flecting medium,  enables  us,  on  the  one  hand,  to  discover 
around  us  innumerable  wonders  otherwise  invisible,  and, 
on  the  other,  to  explore  the  regions  of  immensity,  and 
countless  systems  of  worlds  unseen  by  the  naked  eye. 
The  microscope  is  employed,  not  only  as  a  means  of  dis- 
covering things  otherwise  indiscoverable,  but  also  to 
measure  small  spaces  with  accuracy ;  and  this  application 
of  it  forms  a  marked  period  in  the  history  of  Astronomy. 

The  accuracy  of  results  may  often  be  tested  by  com- 
paring them  with  those  obtained  by  different  processes 
for  effecting  the  same  end,  or  by  observing  whether  they 
lead  to  known  truth  or  falsehood.  Thus,  astronomical 
calculations  of  eclipses  and  other  celestial  phenomena, 
may  be  compared  with  subsequent  observations,  and 
arithmetical  calculations  are  verified  by  reversing  the 
operations,  and  observing  whether  we  arrive  at  correct 
results.  So  the  accuracy  of  a  whole  trigonometrical  sur- 
vey may  "be  verified  by  comparing  the  calculated  with 
the  measured  length  of  the  last  line,  which  is,  therefore, 
termed  "  the  base  of  verification." 

Another  process,  which  is  not  only  a  means  of  testing 
results,  but  frequently  a  most  important  means  of  acquir- 
ing a  knowledge  of  primary  facts,  is,  experiment,  which 
consists  in  operating  with  things,  or  placing  them  in  pe- 
culiar positions,  that  we  may  mark  the  result,  and  thus 
illustrate  a  proposition,  solve  a  difficulty,  or  discover 
some  unknown  truth,  or  some  new  means  of  effecting  a 
known  end.  Experiments  are  either  didactic  or  logical. 
The  former  consist  of  those  which  are  performed  for  the 
purpose  of  illustrating  or  demonstrating  known  truth  to 
learners:  the  latter  comprise  such  as  are  made  for  the 
purposes  of  discovery  or  invention ;  and  it  is  with  these 
alone  that  we  are  concerned  at  present. 

The  immediate  objects  of  most  logical  experiments 
are,  to  determine  the  amount  of  a  certain  thing,  or  one 
or  more  of  its  intrinsic  properties,  or  what  causes  pro- 
duce known  effects,  or  what  effects  are  produced  by 


SEC.  3.]  EXTERNAL  PROCESSES.  91 

known  agencies.  Many  experiments  subserve  two  or 
more  objects.  Thus,  experiments  on  the  composition  of 
water  determine  the  component  elements,  the  quantity 
of  each,  and  the  circumstances  under  which  they  com- 
bine and  separate. 

Experiments  are  generally  requisite  wherever  proper- 
ties, agencies  or  operations  are  hidden  beyond  the  reach 
of  direct  observation  or  measurement,  and  are  discover- 
able only  by  testing  or  trying  them,  with  the  aid  of  all 
that  we  previously  knew  of  the  subject. 

The  nature  of  the  phenomena  of  Comprehension  can 
be  known  only  by  direct  observation.  Thus,  nothing  but 
the  actual  apprehending  can  enable  us  to  know  the  na- 
ture of  our  apprehensions  when  we  smell  a  flower  or 
hear  a  sound ;  and  the  ultimate  processes  of  apprehen- 
sion are  an  inscrutable  mystery.  But,  in  determining  the 
causes  of  phenomena,  experiments  are  frequently  of  much 
use.  Thus,  if  I  doubt  whether  the  table  before  me  act- 
ually exists,  I  may  attempt  to  strike  it,  and  observe 
whether  I  experience  new  apprehensions  when  the  colors 
of  my  hand  and  the  table  come  in  apparent  contact.  So 
we  may  sometimes  learn  how  certain  things  affect  the 
mind,  by  exposing  it  to  their  influence ;  and,  by  exclud- 
ing some  particular  agency,  we  can  occasionally  ascer- 
tain how  much  is  due  to  its  influence  in  other  cases. 

In  many  investigations,  such  as  the  processes  of  Math- 
ematics and  Physics,  little  progress  can  be  made  without 
the  aid  of  visible  symbols,  owing  to  the  great  difficulty 
of  otherwise  remembering  the  various  steps  of  a  process. 
Thus,  ordinary  geometrical  propositions  or  dynamical 
theorems  cannot  be  satisfactorily  investigated  without 
the  aid  of  figures  or  symbols  denoting  quantity.  So  the 
laws  of  many  variable  quantities  can  be  neither  discover- 
ed nor  effectually  remembered,  without  expressing  the 
several  values  either  in  tables,  or  by  curve  lines,  whose 
distances  from  a  point  or  a  straight  line  vary  as  the 
quantity.  Such  are,  the  variations  of  atmospheric  tem- 
perature and  pressure,  of  the  magnetic  needle,  tide-wa- 
ters, the  expectation  of  life  at  different  ages,  and  the 
progress  of  population  in  a  community.  Thus,  if  we  ex- 
press by  a  continuous  curve  the  height  of  the  thermom- 
eter, at  every  hour  of  the  day,  we  can  form  a  correct  es- 
timate of  its  diurnal  variations ;  and  a  similar  curve,  rep- 
resenting its  daily  average  height,  furnishes  the  same  ad- 


92    ACQUIRING  CONTINGENT  KNOWLEDGE.   [CHAP.  III. 

vantage  in  regard  to  its  annual  variations.  So  a  knowl- 
edge and  remembrance  of  the  leading  events  of  History, 
are  much  facilitated  by  synchronistic  tables. 

In  all  cases  of  this  kind,  we  can  dismiss  from  our 
minds,  for  the  time  being,  the  things  denoted  by  the  sym- 
bols, and  concentrate  our  attention  on  the  latter,  while 
we  can  return  to  the  former  whenever  we  require  to  do 
so.  We  remember  the  general  import  of  the  symbols, 
during  the  investigation,  so  as  to  use  them  aright ;  and 
we  can  afterwards  recollect  the  particular  things  which 
they  denote.  Thus,  in  an  algebraic  investigation,  we  can 
remember  which  letters  denote  the  known  and  which  the 
unknown  quantities :  and,  after  the  investigation  is  con- 
cluded, we  can  easily  return  to  the  particular  quantities 
which  every  symbol  denotes. 

Such  devices  as  the  preceding  are  frequently  employ- 
ed to  determine  many  points  which  might  seem  to  be 
matters  of  direct  observation.  Thus,  Kepler  discovered 
that  the  planets  revolve  in  ellipses,  with  the  Sun  in  one 
of  the  foci,  by  representing  their  distances  from  it,  in  va- 
rious parts  of  their  orbits,  on  paper,  drawing  a  curve  line 
through  all  the  points  of  observation,  and  then  determin- 
ing the  nature  of  the  curve,  and  the  exact  position  of  the 
Sun  within  it. 

Curves  are  extensively  employed  in  those  sciences 
which  treat  of  variable  quantities.  They  first  assist  the 
observer,  not  only  in  discovering  the  laws  of  variation, 
but  also  in  eliminating  errors  of  observation :  for,  as  ab- 
rupt transitions  seldom  occur,  in  such  quantities,  a  mere 
inspection  of  the  figure  will  often  enable  him  to  detect 
errors,  by  the  want  of  symmetry  and  regularity  in  the 
curve.  Thus,  if  one  point  of  a  planet's  orbit  be  found  a 
little  without,  and  the  part  immediately  adjacent  a  little 
within  an  ellipse,  the  apparent  discrepancies  might  be 
safely  assumed  to  arise  from  errors  of  measurement, 
since  no  such  deflections  from  its  former  course  can  be 
attributed  to  the  motions  of  the  planet ;  and  hence  it 
might  be  concluded  that  the  true  path  is  an  ellipse.  Aft- 
er the  laws  have  been  discovered,  those  devices  facilitate 
both  the  remembrance  of  them  and  an  understanding  of 
them  by  others. 

Some  representations  are  as  perceptible  to  the  touch 
as  to  sight;  and  these  are  ingeniously  applied  to  com- 
municate knowledge  to  the  blind.  Thus,  by  means  of 


SEC.  1.]          RELIABILITY  OF  MEMORY,  &c.  93 

raised,  instead  of  colored,  letters,  these  unfortunate  per- 
sons are  furnished  with  books  which  they  can  read  by 
running  their  fingers  over  the  letters,  instead  of  seeing 
them ;  and  practice  enables  them  to  do  this  with  sur- 
prising facility. 


CHAPTER  IV. 

OP  THE   PRIMARY   MEANS    OP   RETAINING   KNOWLEDGE. 

§  1.  RELIABILITY  OP  MEMORY,  AND  MEANS  OP  AVOIDING  THE  PRI- 
MARY ERRORS  WHICH  IT  TENDS  TO  PRODUCE. — Use  and  phe^iome- 
na  of  Memory. — Their  possible  sources. — How  the  true  one  is  es- 
tablished.— Indirect  proofs  of  the  reliability  of  Memory. — Common 
errors. — Nature  and  requisites  of  Recognition. — Cases  in  which 
these  generally  exist,  and  in  which  they  fail. — Phantasms. — Why 
Imaginations  are  sometimes  mistaken  for  Ideas. — How  this  error 
may  be  avoided. — Consequence  of  other  Similitudes  recurring  like 
Ideas,  and  of  the  reality  of  all  Similitudes. 

OUR  immediate  knowledge  of  all  contingent  truths  is 
confined  to  the  present  moment.  Thus,  we  can  neither 
see  nor  hear  past  or  future  events,  which  are  made  known 
to  us  only  indirectly,  through  their  being  connected  with 
the  present,  by  means  of  Memory,  Reason,  Abstraction 
and  Conception ;  and  the  aid  of  the  first  of  these  faculties 
is  generally  requisite,  in  all  such  cases,  to  enable  us  to 
pass  beyond  the  present. 

When  objects  of  thought  formerly  apprehended,  are 
again  presented  to  our  observation,  the  ideas  of  them 
arise  spontaneously  before  the  mind,  generally  accompa- 
nied by  those  of  other  objects  apprehended  at  the  same 
time.  These  ideas  sometimes  completely  correspond  to 
the  present  reality,  and  sometimes  there  are  slight  differ- 
ences :  but  there  is  generally  a  close  and  marked  resem- 
blance. In  apprehending  objects  for  the  first  time,  no 
such  ideas  present  themselves.  Many  such  ideas,  again, 
occur  spontaneously,  according  to  certain  laws,  whereas, 
in  order  to  form  conceptions  of  things  never  apprehend- 
ed, we  find  that  a  conscious,  if  not  a  laborious,  effort  is 
requisite.  These  facts  admit  of  no  other  rational  expla- 
nation except  that  we  previously  apprehended  the  pro- 
totypes of  the  spontaneous  ideas,  but  not  the  other  class 
of  objects,  and  that  we  are  still  the  same  persons. 

The  spontaneous  ideas  must  evidently  arise  from  some 


94          MEANS  OF  RETAINING  KNOWLEGE.    [CHAP.  IV. 

fortuitous  peculiarity  of  the  organization,  or  from  some 
conscious  being  designedly  producing  them  directly  ei- 
ther in  the  same  person  who  formerly  apprehended  the 
prototypes  or  in  a  different  person,  or  from  our  having 
actually  apprehended  the  prototypes  of  the  various  ideas, 
and  our  being  so  constituted  that  ideas  of  objects  once 
apprehended  recur  spontaneously,  in  consequence  of  be- 
ing related  to  some  other  thought.  This  last  supposi- 
tion accounts  for  all  the  phenomena;  and  each  of  the 
other  two  involves  an  absurdity. 

The  corresponding  ideas  are  so  numerous,  and,  in  many 
cases,  consist  of  so  many  different  parts,  that  a  fortuitous 
production  is  absurd,  since  it  would  be  a  change  without 
any  adequate  cause.  This  becomes  very  evident  from 
the  fact  that  a  long  succession  of  ideas  often  arises  be- 
fore the  mind  while  we  actually  apprehend  their  proto- 
types, and  in  exactly  the  same  order.  Thus,  if  we  view 
a  well-known  landscape,  the  ideas  of  the  various  objects 
spontaneously  arise,  as  the  eye  beholds  the  successive 
parts,  until  we  see  the  whole  at  a  glance,  when  the  men- 
tal likeness  becomes  equally  complete.  The  supposition 
is  rendered  yet  more  absurd  by  the  fact  that  the  appre- 
hending of  an  object  often  calls  up,  not  only  a  single  idea 
of  it,  but  also  the  similitudes  of  all  our  previous  discern- 
ments regarding  it.  Thus,  the  sight  of  a  well-known 
scene  recalls  the  many  views  we  formerly  had  of  it,  all 
of  which  present  themselves  to  the  mind  simultaneously, 
or  in  very  rapid  succession. 

The  second  supposition,  also,  involves  absurdities.  For 
the  being  which  produced  the  ideas  in  us,  would  be  be- 
nevolent, since  he  often  caused  us  joy,  and  also  malevo- 
lent, since  he  often  caused  pain.  He  must  also  be  desir- 
ous that  we  should  know,  since  he  labored  so  much  to 
produce  elements  of  knowledge ;  and,  at  the  same  time, 
he  must  be  desirous  to  mislead  us,  since  we  actually  in- 
fer, as  the  most  obvious  explanation,  that  we  apprehend- 
ed originals  of  those  ideas.  These  objections  apply  still 
more  forcibly  to  the  supposition  that  he  produced,  in  the 
minds  of  one  person,  ideas  corresponding  to  the  appre- 
hensions of  another. 

That  ideas  correspond  to  their  prototypes,  is  proved 
directly  by  experience ;  for  we  often  find  that  the  appre- 
hensions were  actually  such  as  the  ideas  indicate.  Thus;, 
I  have  the  idea  of  a  certain  writing,  which  I  made  in  a 


SEC.  1.]         RELIABILITY  OF  MEMORY,  &c.  95 

book  yesterday ;  I  turn  to  the  book,  and  there  I  find  it, 
exactly  as  the  idea  indicates.  Again,  I  have  the  idea  of 
a  book  laid  in  a  certain  place ;  I  turn  towards  the  place, 
and  there  I  see  it.  So  the  ideas  of  numerous  instances, 
in  which  Memory  was  found  faithful,  often  arise  before 
our  minds,  and  confirm  its  faithfulness. 

As  the  true  explanation  of  the  phenomena  of  Memo- 
ry is  the  only  obvious  one,  and  we  are  habitually  accus- 
tomed, from  our  earliest  years,  to  draw  the  necessary  in- 
ferences, with  the  proverbial  rapidity  of  thought,  we  are 
apt  to  think  that  we  are  immediately  conscious  of  the  re- 
ality of  things  remembered :  but  it  is  self-evident  that  we 
cannot  be  conscious  of  a  past,  any  more  than  of  a  future, 
contingency.  Mankind  act  here  precisely  as  in  the  case 
of  apprehensions :  they  draw  legitimate  inferences,  but 
mistake  them  for  immediate  discernments,  and  overlook 
other  possible,  though  really  absurd,  suppositions  or  ex- 
planations. 

We  recognize  an  object  when  we  find,  on  comparison, 
that  the  idea  of  it  exactly  resembles  it,  or  very  nearly  so. 
If  the  object  is  not  subject  to  change,  there  must  be  com- 
plete resemblance :  but  if  it  be  subject  to  gradual  changes, 
like  most  organic  beings,  we  consider  whether  the  differ- 
ence between  the  idea  and  the  apprehension  is  not  such 
as  time  may  have  produced,  since  we  apprehended  the 
object.  Thus,  if  we  have  not  seen  a  boy  for  three  years, 
we  make  allowances  for  his  change  of  stature  and  gen- 
eral appearance. 

When  the  idea  is  not  very  clear  or  complete,  we  are 
apt  to  commit  mistakes.  Thus,  we  frequently  take  a  per- 
son not  well  known  or  long  absent,  for  one  who  closely 
resembles  him.  In  order  to  recognize  an  object  with 
certainty,  it  must  possess  some  peculiarity  which  distin- 
guishes it  from  all  similar  objects ;  and  we  guard  against 
the  error  of  mistaking  one  for  another  by  noting  careful- 
ly those  peculiarities,  so  that  they  may  be  remembered, 
and  afterwards  observing  whether  the  object  in  ques- 
tion possesses  them.  Thus,  a  person  otherwise  greatly 
changed  in  appearance,  is  often  recognized  by  some  scar 
or  mark,  which  distinguishes  him  from  all  others.  In 
living  beings,  distinctive  peculiarities  are  generally  found 
without  difficulty,  every  one  having  something  in  form, 
color,  voice,  gait,  or  aspect,  by  which  it  can  be  readily 
identified.  This  is  also  the  case,  to  a  great  extent,  even 


96       MEANS  OF  RETAINING  KNOWLEDGE.   [(JHAP.  IV. 

in  the  vegetable  creation,  and  in  most  inorganic  natural 
objects.  There  are  no  two  trees  or  valleys  in  the  world 
which  cannot  be  readily  distinguished  from  each  other. 
But  works  of  art  frequently  resemble  each  other  so  close- 
ly that  we  cannot,  with  certainty,  distinguish  them.  In 
such  cases,  however,  mistakes  are  generally,  though  not 
always,  of  little  consequence. 

Similitudes  of  conceptions  recur  like  those  of  ideas ; 
and  thus  we  know  what  were  our  former  conceptions. 
But  as  conceptions  are  composed  of  similitudes  or  their 
modifications,  their  phantasms  are  nearly  as  vivid  as  the 
original  elements ;  and  hence  error  is  apt  to  arise  from 
mistaking  them  for  ideas.  This  is  particularly  apt  to  oc- 
cur where  the  phantasms  have  long  been  considered  at- 
tentively, so  that  they  acquire  the  vividness  of  ideas,  for 
which  consequently  they  are  sometimes  mistaken,  as 
where  a  man  gives  a  fictitious  account  of  his  own  per- 
sonal adventures,  with  an  evident  belief  in  their  reality. 

To  avoid  such  errors,  we  have  only  to  recall  the  ideas 
of  the  circumstances  under  which  we  first  conceived  the 
prototypes.  Conceptions  are  always  produced  by  con- 
scious efforts  of  the  Will,  which  distinguish  them  from 
apprehensions  or  ideas.  When  our  remembrance  of  the 
prototype  is  so  faint  that  we  do  not  certainly  know 
whether  it  is  the  similitude  of  a  conception  or  an  appre- 
hension, we  cannot  determine  simply  by  Remembrance 
whether  we  originally  apprehended  or  merely  conceived ; 
and  we  must  have  recourse  to  some  external  means,  in 
order  to  determine  the  truth  of  the  case. 

The  similitudes  of  all  other  thoughts  follow  the  same 
laws  of  recurrence  as  those  of  ideas  ;  and  hence  Remem- 
brance enables  us  to  know  all  our  former  thoughts. 

We  are  as  conscious  of  the  reality  of  similitudes  as  we 
are  of  that  of  their  originals ;  and,  therefore,  we  can  rea- 
son from  the  latter  with  as  much  confidence  as  we  do 
from  the  former,  while  error  must  arise  solely  from  draw- 
ing fallacious  inferences. 

§  2.  PRIMARY  PROCESSES  BY  WHICH  KNOWLEDGE  is  RETAINED. — 
Means  of  knowing  past  Contingencies. — How  we  know  the  Time 
and  Place  of  apprehending. — Forgetting. — Different  simultaneous 
ideas  of  objects. — Recollecting. — Various  kinds  of  External  Signs. 
-^-Principle  of  their  operation. 

Past  contingencies  are  known  by  means  of  things  pres- 


SEC.  2.]  PKIMAUY  PROCESSES.  97 

ent  which  are  signs  or  indications  of  them,  the  things  to 
be  remembered  being  so  connected  with  the  signs  that 
a  knowledge  of  the  latter  leads  to  a  knowledge  of  the 
former.  These  signs  are  either  Internal  or  External. 

Internal  signs  consist  chiefly  of  similitudes,  the  general 
nature  and  operation  of  which  have  already  appeared. 

The  particular  time  and  place  of  apprehending  are  de- 
termined by  means  of  the  ideas  of  objects  apprehended 
.simultaneously :  and  if  these  do  not  appear,  we  know 
only  that  we  apprehended  the  object,  and  cannot  say 
when  or  where.  The  faculty  of  remembrance,  being 
wholly  dependent  on  similitudes,  cannot  act  where  the 
latter  cease  to  arise,  in  which  case  we  are  said  to  forget 
the  apprehension. 

Where  things  have  been  repeatedly  apprehended,  the 
several  ideas  of  them  which  appear  simultaneously,  some- 
times differ.  Thus,  when  we  see  a  person  whom  we 
have  seen  in  health  and  sickness,  the  ideas  of  his  differ- 
ent aspects  frequently  appear  together.  But  the  ideas 
of  the  other  objects  apprehended  on  the  different  occa- 
sions recall  the  various  circumstances,  and  thus  rather 
strengthen  remembrance  and  corroborate  its  testimony, 
than  produce  confusion  or  difficulty. 

Although  ideas  arise  spontaneously,  they  are  always 
suggested  by  some  other  object  of  thought,  which  is  so 
related  to  them  that  thinking  of  the  latter  leads  us  to 
think  of  the  former.  This  peculiarity  enables  us  to  re- 
call ideas  indirectly  when  we  have  lost  the  power  of  do- 
ing so  directly.  Thus,  we  may  have  forgotten  where  we 
saw  a  certain  person,  so  that  we  cannot  directly  deter- 
mine the  place :  but  we  may  know  it  was  on  such  a  day, 
and,  by  recalling  its  transactions,  the  idea  of  the  person 
may  be  brought  up,  with  that  of  the  place  where  we  saw 
him.  In  such  cases,  we  are  said  to  recollect  our  appre- 
hensions. 

External  signs  consist  chiefly  of  direct  likenesses  of 
the  things  to  be  remembered,  symbolic  representations, 
either  of  the  things  or  of  speech,  and  phonetic  signs  of 
words. 

Direct  likenesses  consist  of  sculptures  and  casts,  which 
are  formed  precisely  like  their  originals,  and  of  drawings, 
paintings,  engravings,  or  photographs  of  the  things  to 
be  remembered,  which  only  represent,  on  a  smooth  sur- 
face, their  appearance  in  certain  positions. 

E 


98  GENERALIZATION.  [CHAP.  V. 

Symbolic  representations  of  objects  represent  them  by 
means  of  some  analogy  or  relation  which  they  bear  to 
the  thing  represented,  as  where  a  science  is  symbolized 
by  a  female  figure,  or  a  curve  is  employed  to  point  out 
the  different  values  of  a  variable  quantity,  or  a  great 
event  or  character  is  commemorated  by  a  monument,  or 
periodic  acts  and  ceremonies. 

Symbolic  representations  of  words  represent  them  by 
their  having  some  real  or  fancied  analogy  to  the  thing 
denoted,  or  their  being  arbitrarily,  chosen  for  that  pur- 
pose, such  as — <#,  ?, !,  1,  2,  3,  -f-?  — •>  V ' • 

Phonetic,  signs  consist  of  characters  which  represent, 
not  the  objects  of  thought,  but  the  simplest  elements  of 
speech,  as  «,  #,  c,  &c.  As  those  elements  are  by  no 
means  numerous,  a  few  characters  suffice  to  represent 
the  whole  of  spoken  language. (12) 

All  external  signs  operate  on  the  principle  that  the 
perception  of  the  sign  reminds  us  of  the  thing  signified. 
The  two  things  are  so  connected  that  when  we  perceive 
the  one,  Memory  calls  up  the  other. 


CHAPTER  V. 

OP    GENERALIZATION. 

§  1.  NATURE  or  GENERALIZATION. — Definition  of  Generalization. — 
Conceptions  always  particular. —  All  science  dependent  on  Gen- 
eralization.— Distinction  between  the  formation  of  Conceptions  and 
the  use  of  General  Terms. — What  the  latter  denote. — How  their 
meaning  is  learned. 

Generalization  is,  discovering,  by  means  of  particular 
cases,  general  truths,  or  propositions  which  hold  true  of  a 
whole  class,  such  as — "  the  lion  is  carnivorous" — "  the 
Roman  emperors  possessed  absolute  power" — "men  arc 
mortal,"  and — "  fish  live  in  the  water." 

Not  only  is  every  real  object  in  nature  individual,  but 
our  conceptions  also  are  equally  particular.  Not  only  is 
there  no  general  tree,  river,  house,  or  bird,  in  the  world, 
but  we  cannot  even  conceive  such  things :  we  cannot 
form  a  notion  of  a  tree  that  has  no  form,  size  or  color, 
nor  of  one  that  has  several  forms,  sizes  and  colors.  Such 
conceptions  are  evidently  impossible :  and  when  we  con- 
ceive of  a  thing  as  having  particular  attributes,  the  con- 


SEC.  2.]          NATURE  OF  GENERALIZATION.  99 

ception  is  as  particular  as  any  apprehension.  We  can- 
not conceive  either  of  a  substance  destitute  of  attributes, 
or  of  one  that  possesses  incompatible  attributes. 

Other  things  denoted  by  common  names  are  no  more 
general  than  substantial  beings.  Thus,  there  is  no  gen- 
eral red,  blue,  hardness,  death,  justice,  fraud  or  geome- 
try ;  and  we  cannot  form  a  conception  of  any  such  thing. 
We  cannot  form  a  conception  of  a  red  color  unaccom- 
panied by  any  particular  substance  that  is  red,  or  of  death 
apart  from  any  particular  scene  of  death,  or  of  justice 
apart  from  any  particular  act  of  justice,  and  so  forth. 
Hence  it  appears  that,  without  the  aid  of  Abstraction 
and  Generalization,  our  knowledge  of  nature  would  be 
confined  to  individuals,  and  science  could  not  exist. 

We  must  not  confound  the  formation  of  conceptions 
with  the  use  of  general  terms,  or  Avords  that  apply  equal- 
ly to  every  one  of  a  class  of  objects.  Such  terms  are 
often  used  without  our  having  any  immediate  compre- 
hension of  what  they  denote :  but  this  does  not,  in  the 
least,  prove  that  there  are  general  conceptions.  When 
the  word  "  mountain,"  for  example,  is  mentioned  in  dis- 
course, we  may  possibly  think  of  some  particular  well- 
known  mountain,  or  of  several  mountains  in  quick  suc- 
cession, or  think  of  no  mountain  at  all.  The  last  suppo- 
sition frequently  holds  true,  where  something  besides  the 
thing  meant  by  the  word  is  forced  on  our  attention,  as  in 
the  expression — "  the  word  mountain  is  of  the  singular 
number."  Here  the  attention  is  apt  to  be  wholly  occu- 
pied with  the  words ;  and  a  similar  remark  applies  to 
those  cases  where  we  do  not  require  to  refer  to  the 
meaning  of  certain  signs,  during  an  operation,  after  fix- 
ing them  at  the  beginning  of  a  process  of  reasoning,  as 
generally  happens  in  Algebra. 

A  general  term  is  simply  a  word  which  is  equally  ap- 
plicable to  a  certain  attribute,  action,  or  relation,  wher- 
ever it  exists,  or  to  every  individual  of  a  class.  The 
meaning  of  such  words  is  learned  either  from  observa- 
tion or  definitions.  After  noticing  a  few  cases  or  epcci- 
mens,  we  learn  the  nature  of  the  thing  signified ;  and 
formal  definitions  often  answer  the  same  purpose. 

§  2.  PRINCIPAL  PROCESSES  OF  GENERALIZATION. — (1)  Abstracting 
regarding  some  common  observed  attribute. — Naming  Classes. — 
Empiricisms  and  Inductions. — Requisites  to  the  latter. — Compari- 
son.— (2)  Generalization  from  identity  of  agencies  or  conditions. — 


100  GENERALIZATION.  [CHAP.  V. 

Requisites,  in  such  cases. — On  what  this  process  is  based. — (3)  Rea- 
soning from  the  attributes  which  an  individual  possesses  in  com- 
mon with  a  class. — (4)  Proving  that  all  individuals  of  a  class  have 
certain  attributes  in  common. — Attributes  embraced  in  Definitions. 
— Uniformity  resulting  from  uniformity  of  the  Determining  Agen- 
cies.— Consequences  of  the  Character  of  the  Deity. — Exceptions. — 
Limits  of  physical  Inductions. — Common  Error. — How  the  Uni- 
formity and  Stability  of  Nature  is  logically  established. — Means  of 
distinguishing  Specific  from  Individual  Peculiarities. — Attributes 
common  to  a  Species. — Means  of  detecting  Anomalies. — Princi- 
ples by  which  Inductions  are  established. — Why  Intuitions  do  not 
require  generalization. — What  constitutes  an  Induction. 

The  following  enumeration  includes  the  most  common 
and  important  of  the  processes  of  generalization : 

1.  We  examine  several  objects,  and  compare  them,  ei- 
ther by  direct  simultaneous  inspection  or  by  the  aid  of 
Memory,  and  notice,  by  means  of  the  faculty  of  Abstrac- 
tion, the  attributes  which  they  possess  in  common :  and 
then  we  express  these  in  a  general  proposition,  by  the 
process  of  combination.  In  surveying  animals,  for  ex- 
ample, and  abstracting  as  to  their  external  forms,  we  ob- 
serve that  some,  though  differing  widely  in  other  re- 
spects, all  agree  in  having  four  feet,  as  oxen,  sheep,  dogs 
and  cats ;  some  have  four  hands,  as  monkeys  and  bab- 
oons ;  some  have  two  feet  and  two  feathered  wings,  as 
hens  and  hawks ;  and  man  alone  has  two  hands  and  two 
feet. 

We  may  now  express  the  possession  of  the  common  at- 
tribute by  a  general  proposition,  including  all  the  particu- 
lar ones,  and  give  every  one  of  those  classes  a  name,  equal- 
ly applicable  to  every  individual  belonging  to  it,  and  dis- 
tinguishing it  from  all  others.  Thus,  we  may  call  the 
first  class  quadntped  or  four-footed — the  second,  quadru- 
man  or  four-handed — the  third,  feathered — and  the  last, 
biman  or  two-handed.  Any  other  intelligible  words 
would  suffice  for  the  purpose  of  generalization,  such  as 
simia,  instead  of  quadruman,  bird  or  avis,  instead  of 
feathered,  and  man  or  homo,  instead  of  biman.  There 
is  a  manifest  advantage,  however,  in  having  a  term  which 
denotes  the  essential  peculiarity  of  the  class,  although 
this  cannot  frequently  be  obtained  without  inventing  a 
new  word. 

In  the  same  way  we  generalize  regarding  actions, 
modes  of  action  and  relations.  We  see,  for  instance,  a 
man,  a  dog,  and  a  horse,  all  moving  swiftly  with  a  pecul- 


SEC,  2.]  PRINCIPAL   PROCESSES.  £Ol' 

iar  step,  and  we  denote  this  kind  of  motion  by  the  term 
running.  The  process  of  naming  usually  follows  the  dis- 
covery of  the  general  attribute :  but  it  is  no  essential 
part  of  it,  and  properly  belongs  to  what  is  termed  classi- 
fication, of  which  we  shall  treat  hereafter. 

By  this  method  we  generalize  regarding  all  that  we 
have  actually  comprehended,  which  constitutes  empiri- 
cal generalizations,  or  empiricisms  :  but  to  pass  beyond 
these,  to  scientific  generalizations,  or  inductions,  requires 
other  methods. 

An  empiricism  is,  a  generalization  which  includes  only 
cases  actually  experienced.  An  induction  is,  a  general- 
ization which  is  proved  to  extend  to  the  whole  class  to 
which  it  relates.  "  All  the  horses  that  I  ever  saw,  were 
four-footed,"  is  an  empirical,  and  "all  horses  are  four- 
footed,"  is  an  inductive,  proposition.  To  establish  an  in- 
duction, it  is  requisite,  not  only  that  all  the  things  ob- 
served should  harmonize  with  it,  excluding  only  such  as 
are  mere  exceptions  to  the  general  rule,  but  that  we  have 
some  satisfactory  reason  for  extending  the  empiricism  to 
the  whole  class,  in  which  case  alone  it  becomes  a  scien- 
tific generalization. 

In  comparing  external  objects,  some  or  all  may  be  ab- 
sent :  for  the  ideas  of  them  furnished  by  Memory,  if  suf- 
ficiently distinct  and  accurate,  answer  the  same  purpose 
as  the  original  perceptions.  In  comparing,  we  only  ob- 
serve two  or  more  things  simultaneously,  and  examine 
their  agreements  or  differences,  by  the  aid  of  Abstrac- 
tion :  and  hence  the  faculty  of  Comparison  is  only  a  com- 
bination of  Comprehension  and  Abstraction. 

2.  As  the  same  conditions  or  agents,  operating  in  the 
same  circumstances,  must  always  produce  the  same  re- 
sults, we  generalize  regarding  these  by  ascertaining  what 
they  are  in  one  instance.  Thus,  if  we  find,  by  experi- 
ment, that  a  certain  degree  of  heat  has  melted  iron,  we 
know  the  inductive  proposition  that  such  a  degree  of 
heat  melts  iron. 

In  investigating  the  facts  of  the  particular  instance, 
continued  observations  or  repeated  experiments  are 
sometimes  requisite,  in  order  to  ascertain  the  r~eal  condi- 
tions or  results :  for,  if  we  had  only  one  example,  a  doubt 
might  arise  whether  a  result  was  not  dependent,  at  least 
in  part,  on  other  conditions ;  and,  therefore,  it  is  neces- 
sary to  continue  our  researches,  till  we  have  ascertained 


1G2  -  GENERALIZATION.  [CiiAr.  V. 

the  real  conditions  or  results.     But  where  there  is  no 
room  for  such  doubts,  one  observed  case  is  sufficient. 

3.  By  taking  a  particular  object,  and  reasoning  from 
those  attributes  which  it  possesses  in  common  with  all 
others  of  the  same  class,  we  arrive  at  conclusions  which 
hold  equally  true  of  the  whole  class,  on  the  principle,  al- 
ready stated,  that  conclusions  established  independently 
of  certain  peculiarities,  are  not  affected  by  any  change 
in  these  peculiarities.     Thus,  to  prove  that  "  the  square 
of  the  hypothenuse  of  every  right-angled  triangle  is  equal 
to  the  squares  of  the  two  sides  containing  the  right  an- 
gle," we  take  any  right-angled  triangle,  arid  prove  that 
its  sides  have  this  property,  independently  of  its  partic- 
ular form,  size,  color,  or  position :  and  then,  as  the  rea- 
soning is  independent  of  these  peculiarities,  we  know 
intuitively  that  the  conclusion  holds  equally  true  of  all 
triangles  which  agree  in  being  right-angled,  however 
much  they  may  differ  in  other  respects.   "So  a  multipli- 
cation table  is  constructed  by  first  counting  certain  num- 
bers of  particular  objects ;  and  as  the  amounts  must  al- 
ways be  the  same,  as  long  as  the  numbers  are  the  same, 
the  results  hold  true  universally. 

Inductions  regarding  nature  are  established  in  the 
same  way.  Thus  it  is  shown  that  "  whales  are  mammals, 
and  not  true  fish,"  by  examining  a  single  whale,  and  find- 
ing that  it  breathes  air,  has  a  double  heart,  with  warm 
blood,  and  suckles  its  young,  which  are  the  essential 
characteristics  of  mammals.  As  all  whales  have  these 
peculiarities,  the  particular  species  examined,  its  size,  age, 
and  so  forth,  are  matters  that  do  not,  in  the  least,  affect 
the  truth  of  the  conclusion. 

By  this  means  we  make  an  individual  represent  the 
whole  class  to  which  it  belongs ;  and  thus,  without  act- 
ually examining  more  than  a  few  individuals,  we  obtain 
a  knowledge  of  properties  common  to  the  whole  class. 

4.  In  the  preceding  case,  it  was  assumed  that  every 
individual  of  a  class  has  certain  attributes  in-  common ; 
and  we  now  inquire  how  this  is  known. 

With  respect  to  such  attributes  as  are  embraced  in 
the  definition  of  the  class,  they  must  evidently  possess 
these ;  otherwise  they  would  not  belong  to  it.  Every 
right-angled  triangle  must  have  a  right  angle ;  and  every 
perfect  quadruped  must  have  four  feet;  otherwise  it 
would  not  be  a  quadruped.  But  nature  is  independent 


SEC.  2.]  PRINCIPAL  PROCESSES.  103 

of  our  definitions;  and,  therefore,  we  must  look  beyond 
these,  in  order  to  generalize  satisfactorily  regarding  other 
attributes. 

We  first  observe  several  of  a  class,  till  we  are  satisfied 
that  the  properties  which  they  possess  in  common,  are 
not  owing  to  individual  peculiarities  or  malformations ; 
and  we  then  infer  the  generality  of  these  properties  from 
the  nature  of  the  agencies  which  operate  to  produce 
them. 

We  know,  from  the  phenomena  which  everywhere 
present  themselves  to  our  view,  that  the  same  agencies 
operate  throughout  the  visible  creation.  Hence  it  fol- 
lows, from  the  principles  of  causation,  that  the  same  reg- 
ularity and  uniformity  prevail  in  things  not  observed, 
which  have  been  found  in  those  actually  examined :  oth- 
erwise eifects  would  occur  without  adequate  causes,  and 
different  eifects  would  result  from  the  same  agencies,  op- 
erating in  the  same  circumstances.  Thus,  men  now  pos- 
sess essentially  the  same  physical  constitution  that  be- 
longed to  the  dead,  because  they  have  the  same  origin  ; 
and  they  are  surrounded  and  influenced  by  the  same 
agencies:  hence  we  justly  infer  that  the  living  will  all 
die,  like  their  forefathers.  As  the  circumstances  and 
agencies  are  the  same,  the  results  must  be  the  same  ;  and 
thus  we  arrive  at  the  induction  that  "  all  men  are  mor- 
tal." A  better  observance  of  the  laws  of  health  will  pro- 
long the  average  duration  of  life :  but  it  cannot  essen- 
tially alter  our  physical  constitution,  or  wholly  neutralize 
the  action  of  the  various  causes  which  operate  to  destroy 
it,  so  that  all  the  differences  in  the  circumstances  and 
conduct  of  individuals,  only  affect  the  time  when  they 
will  die. 

This  process  is  applicable  only  to  the  ordinary  course 
of  events,  with  which  it  assumes  that  no  extraneous  or 
peculiar  agency  interferes.  But  the  Deity  may  occa- 
sionally, for  special  and  important  reasons,  adopt  a  pe- 
culiar and  extraordinary  mode  of  proceeding,  contrary 
to  the  usual  course,  or  allow  certain  extraneous  or  un- 
usual agencies  to  interfere  with  the  ordinary  results : 
and  the  occurrence  of  monsters  shows  that  the  latter 
supposition  is  true.  Hence  it  is  only  in  reasoning  from 
intuitions,  hypothetical  assumptions  or  abstract  defini- 
tions, that  our  inductions  are  rigidly  and  universally  true. 
Yet,  as  the  Most  High  is  eternal,  immutable,  omnipotent, 


104  GENERALIZATION.  [CiiAp.V. 

• 

omniscient  and  supremely  benevolent,  he  can  never  act 
from  caprice,  ignorance,  weakness,  malice,  or  any  new 
resolve.  Hence  exceptions  to  the  general  laws  of  nature 
must  be  of  very  rare  occurrence,  so  that  they  detract 
nothing  from  the  practical  or  scientific  value  of  induc- 
tions. The  unconformable  cases  are  only  very  rare  ex- 
ceptions to  a  general  rule;  and  the  circumstances  in 
which  even  these  occur,  frequently  enable  us  to  know 
that  a  particular  case  is  no  exception. 

The  divine  character  informs  us  that  the  same  uniform* 
ity  and  harmony  which  we  now  behold,  must  have  pre- 
vailed since  the  present  order  of  things  began,  and  will 
continue  till  its  termination,  which  appears,  by  various 
proofs,  to  be  still  very  distant.  But  our  inductions  re- 
garding nature  do  not  extend  to  what  may  have  been, 
before  the  present  order  of  things  began,  or  to  what  will 
be,  after  this  planet  has  ceased  to  revolve  in  its  accus- 
tomed orbit :  and  even  within  these  limits,  there  are  few 
physical  inductions  which  have  no  exception.  Most  sub- 
stances have  weight ;  but  light,  heat  and  electricity  have 
none :  ponderable  substances  generally  tend  to  move  to- 
wards each  other ;  but  excited  electrics,  the  similar  poles 
of  two  magnets,  and  the  parts  of  all  compressed  elastic 
bodies,  including  gases,  are  repelled  from  each  other : 
and  fluids  generally  contract,  as  they  cool ;  but  water 
near  the  freezing  point  is  an  exception. 

Where  a  phenomenon  is  the  result  of  a  constant  and 
uniform  agency,  its  generality  is  proved  by  showing  the 
existence  and  nature  of  the  cause.  When  we  trace  the 
changes  of  day  and  night,  and  the  succession  of  the  sea- 
sons, to  the  two  motions  of  the  Earth,  we  discover  that 
those  phenomena  are  as  constant  as  the  course  of  nature ; 
and  the  uniformity  and  stability  of  this  is  shown  in  the 
manner  just  indicated.  Thus  are  established  such  gen- 
eral propositions  as  —  "day  follows  night"  —  "summer 
follows  winter"  —  <fcc.,  which  will  hold  true  till  the  Sun 
ceases  to  shine,  and  the  Earth  to  move,  as  they  now  do. 

The  constancy  and  uniformity  of  nature  has  been  fre- 
quently assumed  from  its  having  been  observed  by  a  very 
narrow  experience,  without  any  .clear  or  thorough  knowl- 
edge of  its  real  foundations :  and  hence  has  resulted  the 
error  of  the  individual  making  his  own  experience  and 
views  a  standard  for  determining  the  laws  of  nature. 
These  can  never  be  logically  established  without  a  refer- 


SEC.  2.]  PRINCIPAL  PROCESSES.  105 

ence  to  the  character  of  the  Author  and  Ruler  of  nature. 
This  is  ascertained  from  particular  facts  or  empirical 
generalizations ;  and,  when  once  ascertained,  it  is  appli- 
cable to  establish,  not  only  the  general  uniformity  and 
stability  of  nature,  but  innumerable  inductions  regarding 
particular  phenomena.  Although  not  always  expressly 
mentioned,  it  is  always  referred  to  in  such  cases :  other- 
wise certainty  would  be  unattainable ;  and  we  could  es- 
tablish only  probabilities.  An  atheist  cannot  logically 
establish  any  physical  or  mental  science,  without  assum- 
ing propositions  which  directly  contradict  the  essential 
peculiarities  of  his  creed. 

In  distinguishing  specific  or  generic  from  individual  or 
accidental  peculiarities,  we  are  aided  by  knowing  that 
certain  properties  are  essential  to  the  perfect  structure 
or  well-being  of  a  class,  while  others  are  not,  even  al- 
though they  may  have  been  found  common  to  every  one 
of  a  class  hitherto  known.  Hence  the  character  of  the 
Deity  proves  that  the  class  must  possess  the  former, 
while  many  of  its  species  or  individuals  may  lack  the 
latter.  A  traveler  of  ordinary  veracity  would  be  enti- 
tled to  credit,  if  he  should  relate  that  he  had  discovered, 
in  some  hitherto  unexplored  region,  a  new  species  of 
crows  which  were  white,  or  a  breed  of  sheep  as  small  as 
rabbits :  for  color  and  size  do  not  affect  the  well-being 
of  a  species,  whose  individuals  often  differ  widely  in  these 
respects.  But,  if  he  should  further  relate  that  he  had 
discovered  a  species  of  bird  which  spent  the  winter  in  a 
dormant  state,  under  water,  or  a  kind  of  sheep  which 
lived  exclusively  on  flesh,  we  should  have  good  reason  to 
conclude  that  he  was  either  mistaken  or  desired  to  mis- 
lead. For  such  animals  could  not  endure,  without  a  per- 
petual miracle ;  and,  therefore,  AVC  might  justly  infer  that 
the  Creator  never  formed  such  beings. 

Among  the  properties  common  to  animal  species,  may 
be  reckoned  the  structure  of  the  nervous  system,  bones, 
muscles,  blood  vessels,  organs  of  sense,  and  digestive  ap- 
paratus. In  vegetables  the  bark,  the  wood,  and  the  form 
and  arrangement  of  the  branches,  leaves,  flowers  and 
seeds,  are  always  alike  in  a  species.  In  inorganic  bod- 
ies, the  individual  attributes  are  generally  common  to 
the  species,  except  form  and  magnitude,  although  there 
are  some  striking  exceptions.  One  piece  of  pure  iron  or 
lime  is  distinguished  from  another  chiefly  by  its  "form 

E  2 


106  GENERALIZATION.  [CHAP.  V. 

and  size.  In  crystals,  even  the  form  is  uniform,  in  the 
various  species. 

A  moderate  acquaintance  with  the  general  structure 
of  organic  beings,  and  the  harmony  of  their  parts,  in  a 
normal  state,  enables  us  to  detect  anomalous  productions, 
with  little  difficulty.  A  naturalist  who  had  previously 
known  nothing  regarding  the  horse,  would  readily  see 
that  one  with  only  three  legs  wanted  a  limb,  while  one 
with  five  had  a  superfluous  organ.  He  has  abundant 
proofs  that  the  Ruler  of  nature  is  able  to  render  every 
being  harmonious  and  perfect  in  its  organization ;  and, 
therefore,  when  he  finds  some  manifest  deviation  from 
that  harmony  and  perfection,  he  justly  infers  the  being 
is  of  monstrous  or  defective  formation,  and  by  no  means 
a  normal  representative  of  its  species,  while,  on  the  oth- 
er hand,  a  perfect  specimen  is  known  by  its  exhibiting 
no  such  deviations. 

All  inductions  are  established  by  means  of  the  prin- 
ciples regarding  determining  conditions  and  agencies 
stated  in  Chapter  II. ;  and  all  the  processes  consist  sole- 
ly of  ordinary  reasoning.  They  are  only  inferences  more 
comprehensive  than  the  premises.  We  infer  that  a  prop- 
osition known  to  hold  true  in  a  few  individual  cases,  is 
equally  applicable  to  the  whole  class  to  which  these  be- 
long. We  may  reason  from  probable,  as  well  as  from 
certain,  premises ;  yet  this  does  not  affect  the  nature  of 
the  process,  which  is  as  uniform  as  that  of  sight  or  hear- 
ing, whether  the  subject  be  Mathematics,  Physics  or  Met- 
aphysics. The  only  difference  is,  that  the  individual  is  a 
perfect  representative  of  a  class,  which  are  all  alike,  in  one 
case,  but  not  always  so,  in  others.  If  we  had  a  horse, 
wrhich  wras  as  like  every  other  horse  as  one  right-angled 
triangle  is  like  another,  we  could  demonstrate  the  prop- 
erties of  every  horse  as  conclusively  as  it  is  proved  that 
the  squares  of  the  sides  containing  the  right-angle  are  to- 
gether equal  to  the  square  of  the  side  opposite. 

Intuitions  are  known  to  be  true  by  direct  conscious- 
ness, even  when  they  are  stated  in  a  universal  form ;  and, 
therefore,  they  require  no  process  of  generalization,  while 
it  is  by  their  means  alone  that  we  ascend  from  the  par- 
ticular facts  of  comprehension  to  a  knowledge  of  general 
contingent  truths. 

It  is  not  the  number  of  observed  cases  which  consti- 
tutes an  induction,  but  the  proof  that  the  observed  attri- 


SEC.  3.]       EXTENSION  OP  GENERALIZATION.  107 

bute  is  general,  which  requires  that  there  be  no  uncon- 
formal»le  cases,  except  such  as  are  anomalous  or  irregu- 
lar. Although  new-year's  day  should  be  found  to  have 
been  stormy,  for  ten  years  in  succession,  this  would  not 
establish  it  as  an  induction  that  it  is  always  so,  whereas 
the  chemical  decomposition  of  a  substance,  in  a  single 
instance,  may  establish  its  composition  as  an  inductive 
truth.  In  the  former  case,  there  is  only  a  fortuitous  co- 
incidence, while,  in  the  latter,  the  previously  discovered 
laws  of  chemical  composition  exclude  such  a  supposition. 
It  is  even  possible  that  all  the  observed  cases  may  be 
contrary  to  the  induction,  as  where  a  person  who  has 
never  seen  a  normal  individual,  is  shown  a  number  of 
monstrous  or  diseased  specimens  collected  by  a  friend. 
So  one  who  never  saw  any  horned  animal  except  Shet- 
land sheep,  might  imagine  that  three  or  four  horns  is  the 
usual,  whereas  it  is  the  exceptional,  number. (13) 

§  3.  EXTENSION  AND  USES  OF  GENERALIZATION. — Superior  and  Sub- 
ordinate Generalizations. — Mode  of  establishing  the  latter,  and  why 
they  are  usually  discovered  first. — Use  of  Empiricisms  and  of  In- 
ductions.— Advantages  of  extending  Generalization. — Empiricisms 
distinguishable  from  Laws  of  Nature. — Evils  arising  from  confound- 
ing them. 

In  the  progress  of  science,  it  is  often  found  that  gener- 
alizations which  were  formerly  considered  ultimate  and 
independent,  are  only  particular  cases  of  a  more  general 
law,  or  common  effects  of  the  same  agency.  In  such 
cases,  the  more  general  law  is  termed  the  superior  or 
higher,  and  the  more  particular  law  or  effect,  the  subor- 
dinate or  special  law.  The  law  that  "  terrestrial  bodies 
tend  towards  the  center  of  the  Earth,"  and  that  "  the 
planets  tend  towards  the  center  of  the  Sun,"  are  only  par- 
ticular cases  of  the  law  of  gravitation. 

The  processes  by  which  we  ascend  from  the  subordi- 
nate to  the  higher  laws,  are  similar  to  those  by  which  we 
establish  the  former.  But,  as  the  higher  include  many 
particular  cases,  a  wider  range  of  observation  is  general- 
ly requisite,  and  the  connecting  points  are  not  so  easi- 
ly ascertained.  Hence  subordinate  laws  are  usually  the 
first  discovered.  In  some  cases,  however,  this  order  is 
reversed.  The  doctrine  of  gravitation  was  established 
before  anything  was  known  regarding  many  of  its  sub- 
ordinate laws.  As  the  general  includes  the  particular, 
the  establishing  of  the  superior  implicitly  establishes  all* 


108  GENERALIZATION.  [CHAP.  V. 

its  subordinate  laws ;  but  these  arc  not  explicitly  estab- 
lished, till  they  are  specifically  known. 

Empirical  generalization  is  necessary,  in  order  to  our 
remembering  and  reasoning  about  any  considerable  num- 
ber of  the  countless  multitude  of  objects  which  fall  un- 
der our  notice :  for,  if  we  attempt  to  view  every  indi- 
vidual as  an  isolated  whole,  and  do  not  attend  to  those 
points  in  which  it  resembles  others,  we  shall  be  confound- 
ed, amid  such  a  chaotic  maze,  and  our  reasoning  will  be 
confined,  in  a  great  measure,  to  individuals.  The  diffi- 
culty is  surmounted  by  forming  empiricisms,  which  ena- 
ble us  to  investigate  an  individual  as  a  proper  represent- 
ative of  a  class,  and  to  comprise  many  particulars  in  gen- 
eral propositions. 

Empiricism  is  also,  in  many  instances,  a  necessary  pre- 
liminary to  induction,  which  is  requisite  in  order  to  our 
performing  many  of  the  duties  of  life,  since  experience 
teaches  us  nothing  regarding  the  future,  or  that  wide 
and  important  part  of  nature  to  which  our  experience 
has  never  extended.  Hence  we  must  go  beyond  empir- 
icisms, in  order  to  know  what  will  result  from  certain 
circumstances,  or  what  we  shall  find,  immediately  beyond 
what  we  now  comprehend. 

The  advantages  of  extending  our  generalizations,  so 
as  to  include  as  many  particulars  as  possible,  are  much 
greater  than  we  might  expect.  Not  only  is  the  Memory 
assisted,  by  being  freed  from  the  necessity  of  retaining 
a  great  variety  of  special  generalizations,  but  the  path  to 
knowledge  is  rendered  shorter  and  more  secure,  while 
the  results  are  frequently  more  abundant.  For  we  have 
only  to  deduce  all  the  logical  consequences  of  the  gener- 
al principle,  in  order  to  establish  them  as  truths,  instead 
of  performing  many  independent  investigations,  and  fre- 
quently relying  on  doubtful  observations  or  testimonies. 
Thus,  the  laws  of  motion  and  gravitation  enable  the  in- 
vestigator of  nature  to  establish  a  great  number  of  im- 
portant laws  in  the  physical  sciences,  many  of  which 
would  otherwise  require  treble  the  labor,  or  could  not 
be  established  at  all. 

Another  great  advantage  of  extensive  generalization 
is,  that  it  enables  us  to  take  a  wider  view  of  the  rela- 
tions which  things  bear  to  each  other,  without  which  a 
knowledge  of  special  laws  is  sometimes  of  comparatively 
little  avail.  For,  as  these  often  result  from  a  more  gen- 


SEC.  3.]  USES  OF  GENERALIZATION.  109 


era!  law,  the  power  which  we  derive  from  a  knowledge 
of  the  latter,  is  as  much  superior  to  what  we  could  ob- 
tain from  a  knowledge  of  special  laws,  as  the  power  of 
permanently  stopping  a  fountain  is  greater  than  that  of 
drying  for  a  time  one  of  several  rills,  while  their  common 
source  continues  to  flow.  If  we  could  discover  the  cause 
of  some  deadly  epidemic,  and  an  effectual  means  of  re- 
moving it,  this  would  be  of  much  more  consequence  than 
the  discovery  of  a  medicine  which  would  cure  only  some 
forms  of  the  disease. 

The  extension  of  induction  is  of  much  importance,  in 
many  instances,  by  exhibiting  a  greater  variety  of  means 
for  effecting  the  same  end.  By  obtaining,  for  example, 
a  more  general  view  of  the  causes  which  produce  a  par- 
ticular effect,  we  are  frequently  furnished  with  a  variety 
of  agents  for  accomplishing  the  same  end,  so  that  when 
one  is  not  within  reach,  we  can  employ  the  other. 

We  should  carefully  distinguish  empiricisms  from  laws 
of  nature,  which  are  always  the  expression  of  an  induc- 
tion, because  much  evil  has  arisen  from  confounding  the 
two  kinds  of  generalization.  The  mere  fact  of  our  hav- 
ing found  a  certain  uniformity  prevailing  within  the  range 
of  our  observation,  does  not  warrant  us  in  assuming  that 
this  uniformity  holds  throughout  nature,  unless  this  can 
be  established  by  some  satisfactory  proof.  Many  lives 
have  been  lost,  owing  to  medical  empiricisms  being  mis- 
taken for  inductions,  and  physicians  consequently  adopt- 
ing an  improper  course  of  treatment,  because  it  had  been 
found  beneficial  in  other  cases,  apparently  similar  but 
really  different. 


CHAPTER  VI. 

OF     II  Y  T  O  T  II  E  S  E  S. 

§  1.  NATURE  AND  USES  or  HYPOTHESES. — Definition  of  Hypotheses. 
— Their  general  value. — Why  their  importance  frequently  over- 
looked.— How  they  promote  close  and  careful  investigation.— In- 
dispensable, in  many  cases. — Their  importance  as  guides. — How 
they  aid  Memory  and  Classification. — Such  uses  independent  of 
their  correctness. — Use  of  Hypotheses  partially  incorrect. — Refu- 
tation of  objections. — Application  to  things  inconceivable. — Use  of 
Hypotheses  in  common  life. — Abuse  of  Hypotheses. 

AN  hypothesis  is,  a  supposition,  made  on  a  subject  of 
which  we  have  some  knowledge,  regarding  something 
still  unknown,  which  we  desire  to  find  out. 


110  HYPOTHESES.  [CHAP.  VI. 

Wherever  the  character  of  the  proposition  in  question 
cannot  be  ascertained  by  direct  observation,  experiment, 
or  reasoning,  we  must  form  an  hypothesis,  and  then  pro- 
ceed to  test  its  truth.  The  importance  of  this  course  is 
evinced  by  the  history  of  the  physical  sciences,  marly  of 
whose  truths  could  have  been  discovered  by  no  other 
means. 

The  confirmation  frequently  given  to  established  hy- 
potheses by  subsequent  discoveries,  is  apt  to  make  us 
overlook  the  means  by  which  they  were  first  proved,  be- 
cause all  other  suppositions  now  appear  so  baseless  that 
we  forget  some  of  them  once  appeared  more  plausible 
than  the  true.  When  this  has  been  ascertained,  the  dis- 
coverer often  confines  himself  to  the  proofs  in  its  favor, 
without  informing  us  of  the  means  by  which  he  first 
made  the  discovery. 

Hypotheses  indirectly  aid  the  progress  of  discovery  by 
their  leading  to  close  discussions  and  extensive  observa- 
tions and  experiments :  for  their  authors  and  upholders 
exert  themselves  to  ascertain  facts  which  may  confirm 
their  own  views,  and  to  detect  misstatements  or  fallacies 
on  the  part  of  their  rivals,  while  the  latter  follow  a  sim- 
ilar but  adverse  course. 

In  many  inquiries,  hypotheses  are  both  unavoidable 
and  indispensable,  because  the  apparent  differ  widely 
from  the  real  facts,  while  the  latter  can  be  ascertained  by 
no  direct  means.  When  we  view  the  heavenly  bodies, 
for  example,  we  must  form  some  supposition  regarding 
their  real  motions ;  and  we  can  determine  these  from 
their  apparent  motions,  only  by  making  several  supposi- 
tions, and  ascertaining  which  is  the  true  one.  In  all 
cases  of  this  kind,  it  is  impossible  to  think  of  the  subject 
at  all,  without  forming  an  hypothesis,  until  some  partic- 
ular hypothesis  has  been  established. 

In  some  cases,  hypotheses,  although  not  indispensable, 
are  of  great  importance,  because  they  enable  us  to  ascer- 
tain what  course  is  likely  to  succeed,  and  what  not. 
Hence  much  time  and  labor  are  saved,  which  would  oth- 
erwise be  wasted  to  no  purpose.  For,  by  considering 
the  various  admissible  suppositions,  and  their  relative 
degrees  of  probability,  we  shall  ascertain  the  truth  much 
more  readily  than  if  we  proceeded  without  any  guidance. 

Hypotheses  also  aid  Memory,  and  assist  us  in  classify- 
ing a  great  variety  of  phenomena,  according  to  some 


SEC.  1.]  USES  OF  HYPOTHESES.  Ill 

logical  principle,  and  ascertaining  their  relations  to  each 
other.  The  observable  phenomena  of  many  subjects  are 
so  numerous,  and  apparently  so  unconnected,  that  we 
can  remember  and  classify  the  facts  and  their  manifest 
relations  to  each  other,  only  by  forming  some  supposi- 
tions regarding  their  causes  and  connections.  Thus,  the 
classification  of  the  various  divisions  of  organic  nature, 
the  remembrance  of  the  peculiarities  of  each,  and  a 
knowledge  of  their  relations,  are  greatly  facilitated  by 
supposing  some  archetype  or  general  model,  which  was 
variously  modified,  in  order  to  produce  the  different 
classes,  and  adapt  them  to  specific  modes  of  living  and 
acting :  for  we  can  thus  most  easily  understand  and  r£- 
member  the  characteristics  of  every  kind,  and  what  rela 
tions  it  bears  to  others ;  after  which  a  proper  classifica- 
tion becomes  comparatively  easy. 

Such  uses  of  hypotheses  are  quite  independent  of  their 
correctness.  Thus,  in  the  case  just  mentioned,  the  sup- 
position that  the  Creator  took  some  form  as  a  model,  and 
variously  modified  it,  to  produce  the  different  classes,  is 
not  only  destitute  of  proof,  but  most  probably  false.  Man 
requires  such  helps,  to  produce  a  variety  of  similar  forms ; 
but  we  have  no  reason  to  believe  that  the  Deity  needs 
any  such  aid.  Yet  it  is  nevertheless  true  that  the  vari- 
ous classes  are  formed  as  if  such  a  model  had  been  em- 
ployed ;  and,  therefore,  the  supposition  is  as  useful  for 
the  purposes  just  mentioned  as  if  it  were  actually  true. 

The  Ptolemaic  system  of  Astronomy  is  another  in- 
stance of  this  kind.  Although  fundamentally  erroneous, 
it  served  to  introduce  some  degree  of  system  and  order 
into  the  complex  phenomena  of  the  heavenly  bodies ;  and 
some  of  its  suppositions  are  so  convenient,  for  several 
purposes,  that  they  are  still  retained  in  various  opera- 
tions, although  they  are  well  known  to  be  false. 

If  an  hypothesis  fundamentally  erroneous  may  be  use- 
ful, much  more  may  one  which  is  only  partially  untrue, 
and  correct  in  the  main,  such  as  the  views  of  Copernicus 
regarding  the  motions  of  the  planets.  He  was  right  in 
supposing  that  the  Sun  was  comparatively  at  rest,  in  the 
center  of  the  system,  with  the  planets  revolving  round  it ; 
but  he  erred  in  supposing  that  they  moved  in  epicycles. 
This  hypothesis  accounted  for  most  of  the  phenomena 
then  known;  and  its  errors  were  such  as  could  not  fail, 
to  be  detected  by  further  observations,  made  with  better 


112  HYPOTHESES.  [CHAP.  VI. 

instruments  than  those  of  that  age.  An  hypothesis  fun- 
damentally correct  generally  indicates  the  course  to  be 
adopted  in  testing  its  details ;  and  hence  the  principal 
difficulty  is  usually  surmounted  as  soon  as  such  an  hy- 
pothesis has  been  established,  although  it  may  be  erro- 
neous in  several  minor  details. 

Hypotheses  also  enable  us  to  refute  objections  urged 
against  a  proposition  of  whose  truth  we  have  satisfactory 
evidence.  We  meet  the  objection  by  showing  what  may 
be,  even  when  we  cannot  prove  that  such  is  actually  the 
case. 

By  means  of  language,  hypotheses  further  enable  us  to 
transcend  the  powers  of  Conception,  and  thus  to  discuss 
things  inconceivable  or  impossible :  for  we  can  suppose, 
for  the  purposes  of  argument  or  examination,  whatever 
can  be  expressed  in  words.  Thus,  although  we  cannot 
conceive  of  an  endless  series  of  events,  or  an  eternal  be- 
ing, we  can  reason  about  them,  as  long  as  our  reason- 
ings do  not  require  us  to  form  any  conception  of  them. 
Much  of  the  utility  of  hypotheses  arises  from  this  power 
of  applying  them  to  any  proposition :  for,  in  many  in- 
stances, it  is  only  by  investigating  and  testing  all  the  pos- 
sible kinds  of  suppositions  regarding  the  subject  under 
consideration  that  we  can  determine  which  is  the  true 
one. 

As  the  term  hypothesis  is  most  frequently  applied  to 
suppositions  on  scientific  subjects,  we  are  apt  to  overlook 
their  great  importance  in  common  life.  Yet  this  is  not 
the  less  real.  In  all  those  cases  where  we  have  to  choose 
between  several  practicable  courses,  we  may  suppose 
them  successively  adopted,  and  trace  the  several  advant- 
ages and  disadvantages  attending  each,  after  which  we 
can  compare  these,  so  as  to  adopt  the  most  eligible.  In- 
calculable evils  have  arisen  from  either  totally  neglecting 
this  process,  or  performing  it  very  hurriedly  and  inaccu- 
rately. We  are  often  so  anxious  to  act,  and  so  impa- 
tient of  delay,  that  we  overlook  the  serious  disadvantages 
of  the  course  we  adopt,  and  the  much  greater  advantages 
of  another.  Hypotheses  of  this  kind  are  often  employed 
without  the  individual  being  aware  of  it,  because  they 
are  made,  and  conclusions  drawn  from  them,  with  such 
extreme  rapidity  that  these  are  taken  for  immediate  dis- 
cernments. 

Hypotheses  are  liable  to  the  great  abuse  of  adopting 


SEC.  2.]  TESTING  HYPOTHESES.  113 

them  as  established  truths,  while  they  are  only  plausible 
suppositions.  Before  adopting  or  admitting  any  hypoth- 
esis as  a  truth,  it  should  first  be  conclusively  established 
by  proof. 

§  2.  METHODS  OP  TESTING  HYPOTHESES. — Tests  of  mathematical  and 
some  other  Hypotheses. — Four  characteristics  of  correct  Hypothe- 
ses regarding  Phenomena.— When  a  phenomenal  Hypothesis  is  es- 
tablished.— Theory. — Principal  means  of  testing  phenomenal  Hy- 
potheses.— Effects  of  increased  knowledge. — Anticipation  of  future 
discoveries. — How  erroneous  Hypotheses  are  sometimes  exploded. 
— Influence  of  discoveries  in  other  departments. — Superior  kind  of 
Hypotheses.  — Cautions. 

In  many  cases,  hypotheses  are  proved  by  simply  find- 
ing that  they  are  necessarily  implied  in  something  al- 
ready known  to  be  true ;  or  they  are  disproved  by  our 
discovering  that  they  involve  errors  or  absurdities.  It 
is  by  such  means  that  all  mathematical  hypotheses  are 
tested ;  and  the  same  processes  are  often  applicable  in 
other  cases  also.  Thus,  the  hypothesis  that  nature  ab- 
hors a  vacuum,  is  disproved  by  the  fact  that  a  vacuum 
occurs  wherever  there  is  no  force  in  operation  to  fill  it. 

To  establish  an  hypothesis  regarding  phenomena  as  a 
truth,  it  must  possess  the  four  following  characteristics. 

1.  The  phenomena  or  appearances  which  it  is  employ- 
ed to  prove  or  explain,  must  be  real  or  actual,  and  not 
merely  supposed  or  assumed.  2.  It  must  not  be  incon- 
sistent with  any  cognition.  3.  It  must  account  for  all 
the  phenomena  in  question.  4.  It  must  be  the  only  hy- 
pothesis which  possesses  the  second  and  third  character- 
istics. 

If  we  overlook  the  first  of  these  conditions,  we  attempt 
to  account  for  what  may  have  no  existence ;  and  we  may 
only  strengthen  error  by  withdrawing  attention  from  the 
nature  of  our  assumptions.  The  second  condition  is  req- 
uisite to  render  the  hypothesis  correct,  so  far  as  it  goes. 
The  third  is  necessary  to  render  it  complete :  for  an  hy- 
pothesis which  accounts  only  for  some  of  a  group  of  con- 
nected phenomena,  must-  be  at  least  defective.  The 
fourth  condition  is  necessary  in  order  to  exclude  other 
hypotheses :  for,  if  one  accounts  for  all  the  facts  as  well 
as  another,  and  contains  nothing  inconsistent  with  known 
truth,  it  is  as  well  entitled  as  any  to  be  received  as  cor- 
rect. 

When  a  phenomenal  hypothesis  has  been  proved  to 


114          .  HYPOTHESES.  [CiiAp.VI. 

possess  those  four  characteristics,  it  ceases  to  be  an  hy- 
pothesis, and  becomes  a  cognition :  and  if  it  consists  of 
a  fundamental  principle,  or  series  of  such  principles,  it  is 
termed  a  theory,  which  implies  something  put  forward  as 
a  truth,  and  considered  such  by  the  propounder,  although 
it  may  not,  in  reality,  be  satisfactorily  established. 

The  principal  means  of  testing  phenomenal  hypothesis 
are,  extended  observation  and  experiment.  An  hypoth- 
esis may  possess  the  three  first  of  the  above  character- 
istics when  it  is  formed :  but  the  progress  of  discovery 
may  refute  it,  by  disclosing  facts  incompatible  with  it,  as 
happened  with  the  Ptolemaic  system  of  Astronomy. 

While  an  erroneous  hypothesis  is  generally  detected 
by  more  extensive  researches,  a 'correct  theory  receives 
confirmation  from  new  discoveries.  Thus,  the  aberration 
of  light,  which  directly  proves  the  motion  of  the  Earth 
in  its  orbit,  was  discovered  by  Bradley,  in  the  eighteenth 
century,  nearly  two  hundred  years  after  the  death  of 
Copernicus :  and,  of  the  lunar  irregularities  now  deduced 
from  the  law  of  gravitation,  more  than  three  fourths  were 
unknown  to  Newton,  who  established  that  doctrine.. 

A  correct  hypothesis  not  only  accounts  for  new  facts, 
after  they  have  been  discovered,  but  it  frequently  enables 
us  to  conjecture  them  beforehand.  Thus,  the  theoretical 
astronomer  has  often  made  discoveries  in  his  study,  which 
were  afterwards  verified  in  the  observatory.  An  erro- 
neous hypothesis,  on  the  other  hand,  is  liable  to  be  ex- 
ploded by  a  single  observation  or  experiment.  Thus, 
the  hypothesis  that  dew  emanates  directly  from  the 
ground,  is  exploded  by  seeing  it  copiously  deposited  on 
a  piece  of  iron. 

An  hypothesis  is  frequently  confirmed  or  refuted  by 
discoveries  made  in  other  departments  than  that  to  which 
it  refers.  Thus,  the  establishment  of  the  undulatory 
theory  of  light  explodes  the  material  theory  of  heat ; 
and  the  progressive  motion  of  light  is  proved  by  observa- 
tions on  the  eclipses  of  Jupiter's  satellites. 

In  determining  which  of  several  admissible  hypotheses 
is  the  true  one,  we  are  often  assisted  by  a  knowledge  of 
the  nature  of  the  various  agencies  which  may  possibly  be 
concerned  in  producing  the  phenomena  under  considera- 
tion, without  further  recourse  to  observation.  Thus,  the 
force  of  gravitation  accounts  for  the  ascent  of  mercury  in 
the  tube  of  the  barometer,  and  of  water  in  the  suction 


SEC.  2.]  TESTING  HYPOTHESES.  115 

pipe  of  a  pump,  so  that  we  may  at  once  discard  the  hy- 
pothesis of  nature's  abhorrence  of  a  vacuum,  or  of  a  pow- 
er of  suction  in  the  tube. 

Of  two  hypotheses,  otherwise  equally  probable,  that 
which  traces  phenomena  to  a  real  agency,  is  entitled  to 
a  preference  over  one  which  attributes  them  to  some  un- 
known cause.  For  the  Ruler  of  nature  has  never  been 
found  employing  two  different  agencies  when  one  would 
accomplish  all  the  results  equally  well.  But  in  those 
cases  where  unknown  agencies  may  possibly  interfere 
with  the  results  deducible  from  a  certain  hypothesis,  these 
ought  to  be  investigated:  for  otherwise  we  know  not 
how  far  such  agencies  may  interfere  ;  and  the  hypothesis 
is  not  legitimately  established  till  it  has  stood  this  test. 
Thus,  the  actual  path  of  a  projectile  through  the  air,  is 
very  different  from  what  is  deduced  from  an  hypothesis 
that  overlooks  the  atmospheric  resistance.  A  cannon 
ball,  fired  off  at  a  certain  angle  of  elevation,  will  go  less 
than  the  twentieth  part  of  its  range,  if  it  moved  in  a 
vacuum. 

Before  applying  hypotheses,  we  should  ascertain  that 
we  have  a  clear  and  accurate  knowledge  of  the  facts  in- 
volved :  for,  if  our  views  of  these  are  confused  or  errone- 
ous, the  use  of  hypotheses  will  be  apt  to  mislead  us,  and 
confirm  us  in  erroneous  opinions. 

We  should  also  beware  of  adopting  any  hypothesis, 
however  plausible,  as  a  truth,  until  we  obtain  decisive 
proof;  and  we  should  discard  it  whenever  we  have  ob- 
tained satisfactory  evidence  that  it  is  erroneous. 


PART  II. 


OF  THE  PRINCIPLES  AND  METHODS  OF 
INVESTIGATION. 


CHAPTER  VII. 

OF   INVESTIGATION   IN   GENERAL. 

§  1.  OF  DISPOSITIONS  AFFECTING  INVESTIGATION. — Common  Error. 
— Advantage  of  Equanimity. — Two  Extremes. — Their  common 
Origin. — Proper  Medium. — Diversity  of  Opinions. — On  what  our 
Attainments  chiefly  depend. — Requisites  to  successful  Investigation. 
— How  the  proper  Disposition  is  to  be  secured. 

THE  investigation,  even  of  the  most  important  sub- 
jects, is  frequently  conducted  in  such  a  way  as  to  be 
worse  than  useless  :  for  it  satisfies  the  individual  that  he 
now  knows  enough  on  these  topics,  and  thus  stifles  fur- 
ther inquiry,  while  it  substitutes  positive  unconscious  er- 
ror in  the  place  of  conscious  ignorance.  In  order  to  act 
more  warily,  we  must  see  the  necessity  for  distrusting 
the  correctness  of  opinions  adopted  without  carefully  ex- 
amining the  foundations  on  which  they  rest. 

If  the  mind  is  strongly  affected  by  some  emotion,  while 
we  are  examining  a  subject,  it  will  both  distract  the  at- 
tention, and  prevent  us  from  taking  a  sufficiently  close 
and  extensive  view  of  the  subject,  so  that  some  import- 
ant points  will  be  considered  inattentively,  and  others 
will  be  wholly  overlooked.  We  should,  therefore,  ab- 
stain from  investigation,  till  we  are  disposed  to  consider 
it  attentively,  and  without  any  passionate  emotion :  oth- 
erwise we  shall  only  fortify  ourselves  in  error. 

Many  have  assumed  that  truth  is  very  easily  discov- 
ered, and  that  men  fall  into  error  owing  to  some  defect 
or  depravity  from  which  they  considered  themselves  en- 
tirely free.  This  state  of  mind  leads  to  adopting,  with- 
out any  proper  examination  of  their  real  nature,  the  first 
plausible  opinions  that  force  themselves  on  the  attention, 
if  not  opposed  to  the  party's  prejudices,  retaining  them 
with  unreasonable  pertinacity,  and  contemning  every  con- 
trary view. 

Many  have  fallen  into  the  opposite  extreme.  They 
have  seen  the  great  diversity  of  opinions  that  has  pre- 
vailed, even  among  the  more  intelligent  portions  of  man- 
kind :  and  hence  they  concluded  that  truth  must  be  very 


120  INVESTIGATION  IN  GENERAL.    [CiiAp.VIL 

hard  to  discover,  or  that  it  cannot  matter  much  whether 
we  discover  it  or  not.  This  class  delight  in  caviling  ob- 
jections, and  in  oppugning  all  the  foundations  of  knowl- 
edge :  they  draw  futile  distinctions,  while  they  overlook 
important  differences,  and  oppose  to  one  set  of  opinions 
the  objections  urged  by  the  disciples  of  another,  without 
ever  carefully  examining  whether  they  are  valid  or  worth- 
less. 

Those  two  extremes  both  originate  from  an  erroneous 
opinion  regarding  the  human  faculties,  and  an  unwilling- 
ness to  undergo  the  labor  of  proper  investigation,  com- 
bined with  various  other  prejudices  and  prepossessions. 
Hence  it  frequently  happens  that  the  same  individual  is 
very  sceptical  regarding  disagreeable  truths,  and  equally 
credulous  and  dogmatic  regarding  agreeable  errors. 

The  proper  disposition  avoids  each  of  those  extremes : 
it  is  ready  to  investigate  aright  the  arguments  in  favor 
of  any  opinion  which  really  deserves  or  requires  investi- 
gation, and  to  adopt  it,  if  these  be  found  conclusive, 
while,  on  the  other  hand,  it  is  prepared  to  reject  every- 
thing which  is  refuted  by  irrefragable  proof. 

The  great  diversity  of  opinions  which  has  prevailed 
among  mankind,  shows  that  truth  is  not  to  be  discov- 
ered without  proper  investigation :  yet  all  the  most  im- 
portant truths  are  placed  within  the  reach  of  ordinary 
abilities ;  and  persons  of  greater  talents  fail  to  discover 
them,  only  when  they  never  search  for  them  aright.  The 
young  inquirer  must  not  imagine  that  certainty  is  unat- 
tainable, even  where  he  finds  conflicting  opinions  held 
by  distinguished  men.  Investigators  whose  principal 
object  was  gain,  applause,  victory,  or  the  gratification  of 
some  darling  prejudice,  could  not  reasonably  be  expect- 
ed to  discover  truth ;  and  we  cannot  rightly  attach  nny 
weight  to  the  opinions  of  the  many  who  have  either 
adopted  the  views  of  others,  without  ever  bestowing  on 
the  subject  an  independent  examination,  or  who  have 
formed  opinions  of  their  own,  without  having  ever  in- 
vestigated it  with  care  and  attention. 

Our  attainments  depend  much  more  on  the  use  we 
make  of  our  faculties  than  on  their  natural  force ;  and 
truth  is  reserved  for  those  who  discard  prejudices,  and 
seek  it  with  proper  care  and  diligence,  without  which 
great  abilities  only  generate  self-conceit,  indolence  and 
error.  If  it  were  more  easily  attainable,  it  would  be  less 


SEC.  2.]  DISPOSITIONS.  121 

valued,  and  sought  more  negligently  and  indolently, 
whence  error  would  abound  more  than  it  does.  Al- 
though the  path  of  the  faithful  inquirer  may  at  first  ap- 
pear gloomy,  yet  the  dark  clouds  raised  by  ignorance 
and  misconception  rapidly  vanish,  as  he  advances,  and  ce- 
lestial radiance  then  cheers  and  guides  his  course. 

In  order  to  successful  investigation,  the  following 
things  are  requisite.  1.  A  correct  estimate  of  the 
value  of  truth,  and  of  the  sacrifices  which  must  be  made 
for  its  attainment.  2.  A  mind  prepared"  to  examine 
properly  every  important  subject,  and  adopt  whatever 
conclusions  truth  dictates.  3.  A  correct  estimate  of 
our  own  capabilities.  We  must  neither  think  that  we 
can  secure  truth  without  a  careful,  continued  and  impar- 
tial examination,  nor  that  it  is  placed  beyond  the  reach 
of  ordinary  abilities  perseveringly  and  judiciously  ap- 
plied. 4.  A  patient  and  active  disposition,  that  we  may 
neither  adopt  a  conclusion  till  we  have  sufficiently  exam- 
ined the  subject,  nor  hesitate  to  investigate  carefully  and 
diligently  all  subjects  having  an  important  bearing  on 
our  welfare. 

The  disposition  proper  for  investigation  is  to  be  at- 
tained by  acquainting  ourselves  with  the  value  of  knowl- 
edge, and  the  evils  of  ignorance  and  error,  the  sources 
of  error,  and  the  requisites  to  successful  investigation. 
For  this  will  produce  an  earnest  desire  to  secure  truth 
and  avoid  error. 

§2.  OF  HABITS  AFFECTING  INVESTIGATION.  —  General  influence  of 
Habits. — (1)  Attention  and  Inattention. — (2)  Methodical  and  de- 
sultory Application. — Advantages  of  a  general  Plan. — Caution. — 
(3)  Wide  and  narrow  views  of  the  subject. — Evils  of  superficial 
and  partial  views. — (4)  Properly  investigating  Proofs,  and  jump- 
ing at  Conclusions. — (5)  Activity  and  Perseverance. — Evils  of  In- 
dolence and  Indifference. — Important  Laws. — (G)  Resisting  Prej- 
udices.— Results  of  being  led  by  our  Wishes. — (7)  Temperance  and 
Self-Control. — Connection  of  Habits. — Evils  of  Self  Indulgence. — 
How  good  Habits  are  to  be  formed. 

Habits  sway  our  conduct  so  extensively  that,  inr  order 
to  successful  investigation,  we  must  form  such  as  are  fa- 
vorable to  that  result,  and  avoid  those  of  a  contrary  kind. 
We  shall,  therefore,  consider  the  former,  and  notice  those 
which  are  opposed  to  their  influence. 

1.  We  have  already  seen  that  all  erroneous  opinions 
are  traceable  to  inattention,  as  their  immediate  source: 

F 


122  INVESTIGATION  IN  GENERAL.    [CHAP.  VII. 

and  it  also  requires  close  attention,  in  many  cases,  in  or- 
der to  discover  the  properties  of  things,  or  their  relations 
to  each  other.  Hence  the  habit  of  close  attention  to  the 
subject  under  consideration  is  necessary  to  guard  us 
against  adopting  errors,  and  enable  us  to  go  beyond  the 
simple  elements  of  knowledge.  It  is  opposed  to  the  habit 
of  considering  a  subject  carelessly,  or  while  our  attention 
is,  at  the  same  time,  fixed  on  something  else,  a  course 
which  inevitably  leads  to  serious  errors.  We  should, 
therefore,  beware  of  tormenting  ourselves  about  small 
matters  and  imaginary  evils,  and  guard  against  the  prac- 
tice of  skimming  along  the  subject  that  we  are  consider- 
ing, without  devoting  to  any  part  more  attention  than  it 
excites  spontaneously :  otherwise  we  cannot,  without 
great  difficulty,  concentrate  our  attention,  even  for  an 
hour,  on  any  subject. 

2.  Several  subjects,  of  the  highest  importance,  cannot 
be  rightly  understood  without  a  continued  degree  of  at- 
tention. Truth  is  not  generally  discovered  at  a  glance, 
but  only  by  a  long  examination,  and  considering  the  sub- 
ject again  and  again.  Now  if  we  rove  from  one  sub- 
ject to  another,  without  devoting  sufficient  time  and  at- 
tention to  each,  our  thoughts  become  more  or  less  con- 
fused, so  that,  when  we  return  to  the  subject  whence  we 
deviated,  we  hardly  know  where  AVC  left  off,  and  find  that 
we  must  begin  again  at  the  starting-point.  Hence  our 
progress  will  be  very  slow  and  unsatisfactory.  Not  un- 
frequently  the  attention  will  be  so  occupied  with  the  sub- 
jects previously  considered,  that  careful  examination  is 
impracticable,  various  things  widely  different  are  con- 
founded with  each  other,  and  many  errors  inevitably  re- 
sult. 

In  order  to  avoid  these  evils,  we  must  acquire  a  habit 
of  considering,  at  the  outset,  the  scope  and  object  of  our 
investigations,  and  of  continued  and  methodical  applica- 
tion. This  is  opposed  to  the  habit  of  flying  from  one 
subject  to  another,  and  taking  up  anything  which  strikes 
the  fancy  of  the  moment,  without  any  definite  aim  or  ob- 
ject, which  leads  to  much  time  being  spent  with  no  oth- 
er result  than  acquiring  many  erroneous  opinions,  and  a 
habit  of  relinquishing  an  investigation  as  soon  as  it  has 
lost  the  charm  of  novelty.  Thus  w^e  come  to  wander 
from  one  subject  to  another,  without  learning  more  of 
auy.thfin  suffices  to  make  us  conceited,  and  satisfied  with 


SEC.  2.]  HABITS.  123 

the  mere  husks  of  knowledge,  while  our  views  may  be, 
in  many  respects,  very  erroneous,  and  we  "may  be  ignor- 
ant of  the  more  important  parts  of  the  various  subjects 
over  which  we  have  been  flying. 

We  should  form  a  general  plan,  which  devotes  a  rea- 
sonable time  uninterruptedly  to  the  various  subjects  of 
our  investigation,  from  which  we  should  not  deviate 
without  some  urgent  and  justifiable  motive,  nor.  farther 
or  longer  than  the  circumstances  warrant.  We  arc  gen- 
erally surrounded  by  temptations  to  turn  aside  from  in- 
vestigation to  things  which  are  immediately  more  at- 
tractive, especially  to  persons  who  do  not  look  beyond 
the  present  moment,  nor  consider  the  tendency  of  desul- 
tory habits,  and  occupying  the  attention  with  matters  of 
no  real  consequence.  Yielding  to  enticements  of  this 
kind  has  been  a  fruitful  cause  of  unsnccessfulness,  among 
those  who  have  desired  and  attempted  to  succeed  in  the 
pursuit  of  truth. 

We  may  investigate  more  than  one  subject  to  advan- 
tage, in  the  course  of  the  day.  But,  in  order  to  this,  we 
must  devote  a  considerable  time  to  each,  and  not  run 
desultorily  from  one  to  another.  Increasing  knowledge 
may  suggest  improvements  in  our  plan,  as  we  advance : 
but  we  should  beware  of  proceeding  without  plan  or  ob- 
ject, which  we  shall  inevitably  do,  unless  we  consider  the 
precise  drift  and  purpose  of  our  investigations.  If  we 
fail  to  do  this,  we  shall  often  begin  an  investigation,  and 
never  finish  it,  whence  we  readily  slide  into  the  habit  of 
clipping  into  every  kind  of  subject,  without  ever  acquir- 
ing a  solid  knowledge  of  any. 

We  should,  therefore,  arrange  our  thoughts  and  ma- 
terials in  the  most  regular  manner  practicable,  and  not 
take  leave  of  the  subject  until  we  have  done  our  best 
to  master  it.  Otherwise  we  shall  fall  into  confusion  of 
thought,  and  abandon  a  subject  before  we  have  begun 
to  understand  it.  Our  investigations  may  be  frequently 
interrupted  by  things  beyond  our  control :  but  this  need 
not  prevent  us  from  returning  to  the  subject  when  the 
cause  of  the  interruption  ceases ;  and  the  habit  of  doing 
so  is  requisite  in  order  to  understand  any  subject  thor- 
oughly. 

3.  The  habit  of  viewing  the  subject  in  its  various  bear- 
ings, and  ascertaining  its  real  character,  is  necessnry  to 
prevent  us  from  overlooking  points  of  great  importance 


124  INVESTIGATION  IN  GENERAL.    [CHAP.  VII. 

or  attaching  undue  weight  to  those  which  we  have  con- 
sidered, to  enable  us  to  see  everything  in  its  true  light, 
and  to  know  the  value  and  application  of  our  attainments. 

This  habit  is  opposed  to  that  of  forming  conclusions 
before  we  have  rightly  examined  the  ichoU  subject,  or  con- 
sidering only  one  of  several  important  bearings,  and  over- 
looking the  rest.  This  leads  to  the  numerous  evils  inci- 
dent to  superficial  or  partial  views,  which  frequently  mis- 
lead as  effectually  as  positive  error,  an  omission  being  as 
fatal  as  a  false  addition.  It  also  leads  us  to  overlook  the 
recondite  and  future  bearings  of  a  question,  which  are 
frequently  very  different  from  the  obvious  and  present 
aspects,  and  of  incomparably  more  importance.  This  er- 
ror is  one  of  the  most  common  and  pernicious  of  all  those 
to  which  mankind  are  liable.  What  is  under  our  imme- 
diate view  is  often  assumed  to  be  a  fair  representation 
of  the  whole,  when  it  is  the  very  reverse. 

This  habit  also  produces  the  error  of  attaching  an  un- 
due value  to  the  least  important  parts  of  a  complex  sub- 
ject, while  we  overlook  or  undervalue  the  most  import- 
ant, and  fail  to  discover  the  true  relations  of  the  various 
parts,  so  that  the  shadow  is  mistaken  for  the  substance, 
and  a  most  inaccurate  and  false  estimate  is  formed  of  the 
whole  subject.  Moreover  it  leads  to  the  great  evil  of 
learning  important  truths,  without  ever  perceiving  their 
practical  applications. 

4.  The  habit  of  'properly  sifting  evidence  or  arguments, 
and  adopting  no  opinion  as  a  cognition  without  con- 
clusive proof  ,  is  requisite,  on  the  one  hand,  to  prevent  us 
from  accepting  a  proposition  as  true  till  we  know  that  it 
is  so,  however  much  we  may  be  prepossessed  in  its  fa- 
vor, and,  on  the  other  hand,  from  rejecting  the  proofs  of- 
fered in  its  favor,  without  due  examination,  however  dis- 
agreeable it  may  be  to  our  wishes.  This  habit  will  pre- 
vent us  from  stopping  short  till  we  have  ascertained  the 
foundations  and  character  of  the  subject,  which  may  be 
very  different  from  what  some  allege  or  believe.  It  is  in- 
dispensable to  the  attainment  of  real  knowledge,  and  the 
avoiding  of  error. 

This  "habit  is  opposed  to  that  of  jumping  at  conclfu- 
sions,  before  we  have  ascertained  the  real  nature  of  the 
proafo  by  which  they  are  supported,  and  assuming  prop- 
ositions as  true  without  any  good  grounds.  This  leads 
u.s  to  adopt  the  erroneous  opinions  of  others,  or  the  die- 


SEC.  2.]  HABITS.  125 

tates  of  our  own  wishes,  as  established  truths.  It  js  very 
easy  to  assume  that  to  be  true  which  we  strongly  desire 
to  be  so,  or  which  is  believed  by  those  around  us,  while 
it  is  frequently  a  difficult  and  laborious  task  to  ascertain 
where  truth  really  lies. 

5.  There  are  so  many  things  to  draw  away  our  atten- 
tion from  the  pursuit  of  knowledge,  and  to  retard  and 
mislead  us  in  our  course,  that,  unless  we  acquire  the  hab- 
it of  working  actively  and  perseveringly,  amid  difficulties, 
discouragements  and  disappointments,  we  may  rest  as- 
sured we  shall  not  be  successful.  It  is  frequently  much 
more  agreeable,  either  to  spend  our  spare  time  in  pas- 
times and  amusements,  or  to  seek  after  knowledge  in  an 
indolent  and  slothful  manner,  than  to  apply  ourselves  act- 
ively and  perseveringly  to  its  attainment.  Hence  many 
have  acquired  the  habit  of  either  using  no  active  exer- 
tion in  acquiring  knowledge,  but  taking  everything  on 
trust,  that  does  not  offend  their  prejudices,  and  rejecting 
everything  that  does,  or  of  giving  up  the  pursuit  as  soon 
as  they  get  into  difficulties,  which  they  speedily  do,  as  a 
matter  of  course  :  and  hence  much  that  has  passed  for 
knowledge,  is  little  more  than  a  web  of  errors  and  mis- 
conceptions. 

It  has  frequently  been  supposed  that  persons  of  com- 
mon abilities  need  not  give  themselves  any  great  trouble 
about  the  acquisition  of  truth  :  for,  if  men  of  great  tal- 
ents failed,  could  they  hope  to  succeed  ?  Undoubtedly 
they  could.  If,  as  has  often  happened,  men  of  great  tal- 
ents are  the  slaves  of  various  bad  habits,  they  will  fail  in 
acquiring  truth,  when  persons  of  much  smaller  abilities 
will  succeed,  provided  they  avoid  such  habits,  and  make 
the  most  of  the  powers  which  they  possess.  Difficulties 
are  encountered  even  by  the  most  gifted,  who  are  gener- 
ally obliged  to  toil  long  and  arduously,  in  order  to  ef- 
fect great  results.  If  we  do  our  best  to  acquire  knowl- 
edge, we  shall  never  be  disappointed :  for  although  it  is 
a  law  of  nature  that  great  good  is  never  secured  'without 
great  labor,  it  is  equally  a  law  of  nature  that  persevering 
care  and  diligence  will  overcome  every  obstacle  to  the  at- 
tainment of  the  most  important  knowledge. 

It  requires  neither  uncommon  abilities  nor  wealth,  in 
order  to  master  the  most  important  truths  within  the 
circle  of  human  attainments.  Bad  habits  are  a  much 
greater  bar  to  progress  than  want  of  abilities  or  money  ; 


126  INVESTIGATION  IN  GENERAL.    [CHAP.  VII. 

and,  of  these,  habits  of  indolence  and  indifference  are  by 
no  means  the  least  powerful.  Gold  may  purchase  mate- 
rial wealth:  but  it  neither  secures  truth  nor  excludes 
error.  These  objects  require  persevering  and  careful 
toil  from  the  rich  as  well  as  from  the  poor ;  and  experi- 
ence has  shown  that  the  disadvantages  of  the  former  are 
greater  than  those  of  the  latter. 

6.  Not  the  least  important  of  good  habits  is,  that  of 
investigating  candidly,  without  yielding  to  the  influence 
of  prejudices^  which  are  among  the  most  fertile  of  all  the 
sources  of  ignorance  and  error.     They  frequently  pre- 
vent investigation  altogether,  and  still  more  frequently 
render  it  abortive,  by  leading  to  the  adoption  of  errone- 
ous opinions. 

This  habit  is  opposed  to  that  of  allowing  our  wishes  to 
turn  away  the  attention  from  certain  parts  of  the  subject, 
and  to  mew  the  rest  hurriedly  and  negligently,  a  course 
which  inevitably  leads  to  error.  Our  wishes  do  not,  in 
the  least,  change  the  nature  of  truth  and  falsehood  ;  and, 
in  order  to  discriminate  these  from  each  other,  we  must 
view  a  subject  as  it  is,  and  receive  or  reject  proofs  ac- 
cording to  their  real  character.  We  must  receive  as  true 
what  is  sustained  by  conclusive  proof,  however  unac- 
ceptable, and  reject  whatever  is  destitute  of  such  proof, 
however  agreeable. 

7.  Habits  of  temperance  and  self-control,  or  resisting 
the  solicitations  of  desires  and  appetites  which  ought  not 
to  be  gratified,  are  essential  to  the  successful  pursuit  of 
truth.     Dissipated  and  luxurious  habits  form  an  insur- 
mountable obstacle  to  great  progress  in  the  attainment 
of  knowledge,  white  they  tend  strongly  to  root  out  all 
good  habits,  and  introduce,  in  their  place,  those  which 
are  incompatible  even  with  the  retention,  and  much  more 
with  the  acquisition,  of  knowledge.    The  investigator  of 
important  subjects  must,  in  order  to  be  successful,  not 
only  abstain  from  such  things  as  are  pernicious  in  any 
degree,  but  also  guard  against  going  beyond  the  bounds 
of  moderation  in  what  is  proper  and  allowable.    It  is  not 
enough  to  avoid  the  extreme  of  a  debauch :  he  ought  to 
shun  the  excesses  of  gluttony,  exciting  and  frivolous  pas- 
times, and  the  intoxicating  paroxysms  and  reactive  pros- 
trations of  ungoverned  passions. 

We  are  incessantly  tempted  to  forsake  the  pursuit  of 
knowledge  altogether,  or  to  investigate  hurriedly,  and 


SEC.  3.]  HABITS.  127 

without  due  caro  and  attention,  for  the  sake  of  present 
gratification,  or  escaping  from  present  pain  or  uneasi- 
ness :  and,  unless  we  resolutely  refrain  from  indulging 
such  desires,  the  successful  "pursuit  of  truth  becomes 
hopeless.  . 

This  habit  is  not  only  of  great  importance  in  itself,  but 
it  is  indispensable  to  the  existence  of  other  good  habits, 
which  will  be  speedily  undermined,  if  we  habitually  yield 
to  the  desires  of  the  present  moment.  The  attention  will 
be  distracted ;  the  subject  will  be  investigated  carelessly 
and  immethodically ;  we  shall  be  misled  by  prejudices ; 
our  inquiries  will  be  conducted  without  vigor  or  perse- 
.verance;  and  consequently  error  will  usurp  the  place  of 
truth. 

Those  habits  are  opposed  to  that  of  self-indulgence^ 
and  sacrificing  important  future  good  for  the  sake  of 
a  fleeting  present  gratification,  or  exemption  from  tran- 
sient pain  or  toil,  which  is  the  most  fertile  of  all  the 
sources  of  error,  and  the  great  barrier  to  the  removal  of 
ignorance.  Its  votaries  dislike  study,  because  it  is  less 
pleasant  to  their  dark  minds  and  groveling  tastes  than 
gross  enjoyments  or  frivolous  amusements  ;  and  when 
the  consideration  of  an  important  subject  is  forced  on 
their  attention,  they  gladly  avail  themselves  of  any  falla- 
cy that  first  presents  itself,  to  quiet  their  consciences  for 
not  examining  it  aright.  They  generally  adopt  those 
opinions  which  are  most  agreeable  to  their  prejudices, 
without  ever  carefully  examining  whether  they  are  true 
or  false ;  and  if  by  chance  they  come  to  see  that  any  of 
these  is  untenable,  they  usually  supply  its  place  with 
some  similar  error. 

In  order  to  form  good  habits,  we  must  obtain  the  dis- 
position proper  for  successful  investigation,  then  consider 
the  subject  till  we  understand  the  nature  and  operation 
of  those  habits,  and  finally  practice  them,  and  shun  the 
contrary  habits.  When  once  fairly  adopted,  this  course 
becomes  easy,  as  good  habits  are  much  more  pleasant,  in 
the  long  run,  than  bad,  and  that  which  has  become  ha- 
bitual is  easily  done,  from  the  fact  that  it  is  habitual. 

§  3.  OF  THINGS  WHICH  REQUIRE  NO  PROOF. — Why  Intuitions  require 
no  Proof,  nor  Apprehensions. — Reality  of  Conceptions  and  Simili- 
tudes.— General  expression  of  what  needs  no  Proof. — Truths  which 
admit  of  no  logical  Proof. — Sole  pre-requisites  to  their  admission. 

As  the  proof  of  a  proposition  is,  that  which  shows  that 


128  INVESTIGATION  IN  GENERAL.    [CiiAr.  VII. 

it  is  true,  either  absolutely  or  conditionally,  intuitions  re- 
quire no  prtfof,  because  they  are  self-evident ;  and  there- 
fore no  proof  could  add  to  their  certainty,  while  we  could 
attempt  to  prove  them  only  by  assuming  something  tan- 
tamount to  themselves. 

With  respect  to  apprehensions,  we  have  already  seen 
that  they  are  matters  of  immediate  consciousness,  the 
reality  of  which  admits  of  no  rational  doubt;  and  proof 
is  as  superfluous  as  in  the  case  of  intuitions. 

Ideas  are  equally  known  by  immediate  discernment. 
When  the  idea  of  a  well  known  person  or  place,  for  ex- 
ample, is  present  to  the  mind,  we  know  certainly  that 
we  discern  such  an  idea,  and  that,  if  we  did  not,  it  could 
not  exist,  although  its  origin,  or  whether  it  ever  had  a 
prototype,  is  another  question. 

A  similar  remark  applies  to  conceptions.  When  we 
form  a  conception  of  a  whale  or  a  sphinx,  for  example, 
we  know  that  we  actually  discern  the  phenomenon. 
Whether  the  likeness  is  correct,  or  whether  such  an  ani- 
mal really  exists,  are  questions  which  do  not  in  the  least 
affect  the  reality  of  the  conception. 

All  our  comprehensions,  including  apprehensions,  con- 
ceptions, and  similitudes,  are  equally  and  certainly  real ; 
for  unless  they  were  so,  they  evidently  could  not  exist. 
They  are  all  precisely  What  they  appear  to  be,  without 
any  possibility  of  error,  which  affects  only  the  inferences. 

Hence  it  appears  that  truths  of  Intuition  and  Compre- 
hension require  no  proof,  which  may  be  more  briefly  ex- 
pressed thus :  discernments  require  no  proof. 

Moreover  all  attempts  to  establish  these  truths  are 
necessarily  fallacious,  since  they  must  assume  the  very 
propositions  which  are  intended  or  professed  to  be 
proved.  Thus  we  cannot  proceed  a  step  to  prove  the 
reliability  of  Consciousness  without  assuming  this  as  true, 
and  all  our  processes  necessarily  involve  that  assump- 
tion. (14) 

Before  admitting  a  proposition  as  a  discernment,  all 
we  require  to  know  is,  that  it  really  belongs' to  this  class 
of  truths.  We  are  indeed  liable  to  take  for  self-evident 
even  things  which  are  self-evidently  impossible ;  and  we 
sometimes  assume  fallacious  inferences  to  be  immediate 
comprehensions.  Yet  all  that  is  necessary  to  distinguish 
discernments  from  all  other  propositions,  is,  an  attent- 
ive and  close  consideration.  That  which  is  really  self- 


SEC.  4.]  THINGS  ADMISSIBLE.  129 

evident,  will  clearly  appear  to  be  such  when  well  under- 
stood and  carefully  considered ;  and  the  same  process 
will  readily  distinguish  comprehensions  from,  inferences. 

§  4.  OF  THINGS  WHICH  MAY  GENERALLY  BE  ADMITTED  AS  PROVED. 
— How  mediate  Knowledge  is  established. — Twofold  division  of 
Proofs. — Evidence. — Signs. — Testimony. —  Deduction. — Primary 
foundations  of  sound  Reasoning. — Why  frequently  unnecessary  to 
trace  reasoning  to  these. — Mode  of  proceeding  regarding  External 
Objects. — (1)  Principle  regarding  the  causes  of  Apprehensions. — 
Chief  source  of  Error. — How  avoided. — Indications  of  Disease. — 
Circumstances  in  which  the  organs  are  liable  to  mislead. — Imita- 
tions of  Nature. — Real  source  of  many  Mistakes  attributed  to  the 
Senses. — General  nature  of  Apprehensional  Errors. — (2)  Principle 
regarding  Remembrance. — Chief  source  of  Errors  attributed  to 
Memory. — How  they  may  be  avoided.— (3)  Principle  regarding 
Testimony. — Origin  of  Falsehoods. — When  we  may  assume  testi- 
mony to  be  correct. — What  things  require  formal  proof. 

As  all  knowledge  is  either  mediate  or  immediate,  that 
which  does  not  belong  to  the  latter  must  fall  under  the 
former;  and  cognitions  of  that  class  are  established  by 
ascertaining  that  they  are  necessarily  connected  with 
our  immediate  knowledge,  that  which  shows  this  con- 
nection being  termed  the  proof. 

All  proof  is  either  evidence  or  deduction,  or  a  combi- 
nation of  both. 

Evidence  is,  any  contingent  fact  which  goes  to  estab- 
lish the  proposition  in  question.  It  consists  of  signs  and 
testimony. 

A  sign  is,  something  observed  or  comprehended  by 
ourselves,  which  proves  the  thing  in  question  by  being 
its  uniform  antecedent,  concomitant,  or  consequent,  or 
by  being  directly  and  manifestly  incompatible  with  its 
falsity.  Signs  are  either  internal,  consisting  of  the  phe- 
nomena of  Memory  and  other  internal  comprehensions,  or 
external,  which  consist  of  indications  discernible  by  Ap- 
prehension. These  comprise  every  apprehension  which 
is  known,  either  by  experience  or  Intuition,  to  imply  di- 
rectly the  past,  present  or  future  existence  of  something 
different  from  itself*  so  that  most  of  our  apprehensions 
belong  to  this  class,  3nd  many  of  them  are  signs  of  vari- 
ous things.  A  sign  indicates  the  past,  the  present,  or  the 
future,  according  as  it  is  a  consequent,  concomitant  or 
antecedent  of  the  thing  signified  or  indicated. 

Testimony  is,  a  statement  made  by  another  regarding 
what  he  professes  to  have  comprehended  or  to  think.  It 

F  2 


130  INVESTIGATION  IN  GENERAL.    [CHAP.  VII. 

may  either  state  the  very  thing  in  question  from  the  wit- 
ness's own  knowledge  or  some  sign  of  it  which  he  pro- 
fesses to  have  comprehended,  or  it  may  only  declare 
what  he  has  heard  from  other  witnesses. 

Deduction  consists  of  reasoning,  which  professes  to 
show  that  the  proposition  in  question  is  necessarily  im- 
plied in  something  which  either  requires  no  proof  or  is 
already  known,  by  some  means,  to  be  true,  or  is  merely 
assumed  to  be  so ;  and  it  is  tested  by  the  criterions  of 
reasoning  formerly  mentioned. 

If  sound  reasoning  be  traced  to  its  foundations,  we 
shall  always  arrive  at  intuitions,  comprehensions  or  sup- 
positions, as  the  primary  premises,  because  these  are  the 
only  possible  sources  of  mediate  knowledge.  But  such 
a  thorough  investigation  is  generally  unnecessary :  for 
when  certain  connections  have  once  been  established, 
they  may  be  taken  as  proved,  in  all  subsequent  inquiries. 
We  assume  what  has  been  already  proved,  and  proceed 
thence,  as  a  new  starting  point. 

When  we  have  once  clearly  ascertained  the  connec- 
tion between  certain  apprehensions  and  their  external 
causes,  we  generalize  precisely  as  in  other  cases,  and 
thenceforth  assume  that  the  same  phenomena  have  the 
same  or  similar  causes.  So,  when  we  have  once  ascer- 
tained that  the  phenomena  of  Memory  must  represent 
real  prototypes,  we  assume  this  for  the  future.  When 
we  see  certain  complements  of  colors,  and  hear  certain 
sounds,  for  example,  we  assume  that  these  are  caused  by 
such  and  such  substances,  without  or  beyond  ourselves : 
and  when  certain  groups  of  ideas  spontaneously  arise, 
wre  assume  that  we  apprehended  their  originals,  without 
waiting  to  discuss  the  various  possible  sources  of  those 
ideas. 

We  shall  now  mention  the  cases  in  which  such  assump- 
tions may  be  safely  made,  and  the  errors  against  which 
we  have  to  guard,  supposing  the  requisite  degree  of  at- 
tention has  been  bestowed  upon  the  immediate  compre- 
hensions. . 

1.  Apprehensions  may  be  assigned  to  be  caused  by 
agencies  similar  to  those  which  were  found  to  have  caused 
such  phenomena  formerly.  If,  for  instance,  we  see  those 
colors  and  hear  those  precise  tones,  which  we  formerly 
apprehended,  as  Remembrance  shows,  when  a  certain 
friend  addressed  us,  we  may  assume  that  the  same  friend 


SEC.  4.]  THINGS  ADMISSIBLE.  131 

is  now  present  and  addressing  us.  Here  the  principal 
source  of  error  is,  assuming  that  the  same  phenomena 
must  have  resulted  from  agencies  precisely  similar,  if  not 
the  same,  whereas  these  may  be,  in  some  respects,  differ- 
ent. We  are  apt  to  attribute  a  phenomenon  to  the  very 
same  agencies  which  produced  similar  phenomena  in  our 
previous  experience,  overlooking  the  possibility  of  their 
being  caused,  in  some  cases,  by  agencies  in  several  re- 
spects different. 

To  guard  against  this  error,  we  must  ascertain  that  a 
phenomenon  can  be  rationally  attributed  only  to  one 
cause  or  set  of  agencies.  Such  is  the  uniformity  of  na- 
ture, that  deceptions  of  this  kind  form  only  rare  excep- 
tions to  a  general  rule.  The  principal  sources  of  illusion 
are,  a  diseased  state  of  the  apprehending  organs,  and  in- 
tentional imitations,  which  exhibit  phenomena  that  are 
usually  caused  by  a  different  combination  of  circum- 
stances. When  our  organs  are  healthy,  the  various  be- 
ings that  surround  us  affect  them  with  great  uniformity. 
Thus  we  readily  distinguish  the  countenance  of  one  friend 
from  that  of  another ;  and  we  are  in  no  danger  of  mis- 
taking the  smell  of  a  rose  for  that  of  an  apple,  although 
both  belong  to  the  class  of  fragrant  odors. 

Disease  of  our  organs  is  generally  indicated  by  com- 
prehensible signs ;  and  it  is  only  when  the  morbid  affec- 
tion is  violent  or  extensive  that  we  are  apt  to  be  misled 
at  all,  while,  in  such  cases,  the  indications  of  disease  are 
generally  palpable.  Thus,  a  slight  inflammation  of  the 
eyes  does  not  prevent  us  from  accurately  distinguishing 
colors,  and  ordinary  affections  of  the  ear  only  increase  or 
diminish  its  usual  degree  of  sensibility.  When  disease 
lias  been  violent  and  long  continued,  all  mistakes  are  ob- 
viated by  the  organ's  ceasing  to  perform  its  functions. 
The  blind  make  no  mistakes  regarding  colors,  nor  the 
totally  deaf,  regarding  sounds.  It  is,  therefore,  only  in 
particular  cases  of  disease  that  mistakes  are  liable  to  be 
committed ;  and,  in  these  cases,  we  are  put  on  our  guard 
by  palpable  indications  of  the  affection! 

With  respect  to  imitations  of  nature,  we  generally 
know  in  what  circumstances  they  are  to  be  expected, 
and  they  are  seldom  so  complete  as  to  escape  detection, 
on  a  close  inspection.  A  juggler  uses  sleight  of  hand  ; 
but  this  is  out  of  the  question  in  our  ordinary  intercourse 
with  friends.  So,  a  distant  figure,  seen  at  the  end  of  a 


132  INVESTIGATION  IN  GENERAL.    [CHAP.  VII. 

long  passage,  may  possibly  be  a  statue  ;  but  if  we  notice 
a  similar  appearance  in  a  lonely  uninhabited  place,  we 
justly  infer  that  it  is  a  real  person.  Again,  a  skilfully 
executed  painting  may  be  mistaken  for  its  original,  espe- 
cially when  seen  from  a  distance  or  in  an  obscure  light ; 
but,  on  a  close  inspection,  the  resemblance  is  hardly  ever 
complete ;  and  even  when  viewed  from  some  distance, 
its  unchanging  appearance,  as  it  is  surveyed  from  vari- 
ous points,  distinguishes  it  from  a  solid  object.  A  ven- 
triloquist may  imitate  the  pitch  of  the  voice,  to  some  ex- 
tent, so  as  to  deceive  us  regarding  the  distance ;  but  as 
he  cannot  aifect  the  directions  in  which  the  undulations 
strike  the  ear,  without  turning  his  voice  into  a  mere  echo, 
the  origin  of  his  utterances  may  always  be  detected. 

Intentional  imitations  must  proceed  from  some  mo- 
tive ;  and  as  they  generally  require  time  and  skill,  they 
are  seldom  attempted,  without  some  motive  stronger 
than  a  momentary  whim.  An  extensive  acquaintance 
with  the  laws  of  nature,  both  mental  and  physical,  would 
obviate  every  mistake  of  any  consequence,  likely  to  arise 
from  this  source. 

Many  of  the  mistakes  which  are  attributed  to  illusions 
of  the  senses,  arise  solely  from  inattentive  observation, 
without  apprehension  being  in  the  least  at  fault.  Thus, 
we  sometimes  mistake  one  person's  voice  or  countenance 
for  another's,  which  it  resembles,  although  a  little  close 
observation  would  show  that  there  are  peculiarities  by 
which  they  can  be  easily  distinguished. 

2.  TJie  clear  presentations  of  Memory  maybe  assumed 
to  represent  real  originals,  and  prove  our  personal  iden- 
tity. The  processes  by  which  we  ascertain  the  connection 
between  ideas  and  their  prototypes,  incidentally  prove 
our  personal  identity,  so  far  back  as  Memory  extends. 
For  it  consists  in  continuity  and  similarity  of  thoughts, 
the  corporal  changes  which  incessantly  occur  having  no 
influence  on  it ;  and  it  would  be  as  little  affected  by  sim- 
ilar mental  changes,  even  if  they  existed,  which  they 
probably  do  not.  Our  identity,  and  the  reliability  of 
Memory,  having  been  once  ascertained,  they  are  after- 
wards rightly  assumed,  without  any  formal  repetition  of 
the  processes  by  which  they  were  first  discovered. 

The  principal  sources  of  error  connected  with  Remem- 
brance are  the  following.  (1)  Overlooking  the  peculiar- 
ities which  distinguish  ideas  from  phantasms,  whence 


SEC,  4.]  THINGS  ADMISSIBLE.  133 

they  are  confounded,  and  we  suppose  that  we  apprehend- 
ed what  we  only  conceived,  (2)  Overlooking  the  pecu- 
liarities which  distinguish  one  similitude  or  apprehension 
from  another.  As  the  power  of  Memory  is  much  strong- 
er than  that  of  Conception^  mistakes  of  the  former  sort 
are  very  rare.  They  occur  chiefly  where  a  lively  con- 
ception is  formed  of  a  particular  thing,  and  its  phantasm 
is  frequently  considered,  while  the  ideas  of  the  things  ap- 
prehended when  it  was  formed  are  forgotten.  Mistakes 
of  the  second  kind  are  very  common.  We  often  mistake 
one  thing  for  another,  for  instance,  because  we  overlook 
the  peculiarities  which  distinguish  them,  and  which  close 
observation  would  readily  detect. 

In  all  cases  where  errors  are  attributed  to  Memory,  it 
will  be  found  that  they  are,  in  reality,  attributed  to  un- 
sound reasoning,  or  to  hasty  and  inaccurate  observation. 
When  a  thing  is  quite  forgotten,  Memory  cannot  mislead 
us  regarding  it,  any  more  than  if  we  had  never  known 
it;  and  when  the  idea  is  faint,  or  unaccompanied  by 
those  of  the  other  things  apprehended  at  the  same  time, 
yet  it  is  real,  and  its  character  suggests  caution  in  draw- 
ing inferences. 

In  our  own  case,  a  very  moderate  degree  of  attention 
will  show  us  to  which  class  a  certain  similitude  belongs. 
If  it  be  clear,  and  accompanied  by  equally  clear  simili- 
tudes of  the  other  things  comprehended  simultaneously, 
we  justly  infer  that  all  were  so  comprehended.  When 
the  case  is  otherwise,  we  should  suspend  a  judgment  till 
wre  can  obtain  some  extraneous  aid,  such  as  that  of  notes 
or  memorandums  made  by  ourselves,  or  some  evidence 
proceeding  from  others.  By  this  means  we  may  avoid 
errors  proceeding  from  our  own  Memory. 

In  the  case  of  other  persons,  the  only  difference  is, 
that  they  may  misrepresent  the  actual  nature  of  their 
similitudes.  This  point  may  possibly  be  determined 
from  cross-questioning,  from  their  general  character,  from 
the  special  relations  which  their  views  and  interests  bear 
to  the  testimony,  from  comparing  their  statements  with 
those  of  other  persons,  or  from  facts  ascertained  by  any 
other  means. 

3.  Things  testified  by  credible  witnesses  may  be  as- 
sumed as  true,  so  far  as  their  actual  experience  extends. 
To  invent  a  falsehood  requires  an  effort,  as  it  never  arises 
spontaneously,  the  similitudes  of  things  actually  compre- 


134  INVESTIGATION  IN  GENERAL.    [CHAP. 

hended  being  always  presented,  except  where  the  Will 
interferes  with  this  result;  and  the  utterance  of  false- 
hood is  always  followed  by  thoughts  more  or  less  pain- 
ful, even  where  it  escapes  detection.  Hence  no  person 
will  relate  a  falsehood,  without  some  particular  motive ; 
otherwise  it  would  be  an  effect  without  any  adequate 
cause :  and,  therefore,  where  there  is  either  no  motive  or 
none  that  could  operate,  there  will  be  no  wilful  false- 
hood. Erroneous  statements  must  arise,  either  from  the 
relator's  unwillingness  or  his  inability  to  state  what  he 
knows  to  be  true,  or  frpm  his  having  been  misled ;  and 
hence,  when  there  is  no  room  to  doubt  the  veracity  or 
the  ability,  memory  and  opportunities  of  a  witness,  we 
may  safely  assume  that  his  testimony  is  correct,  as  to 
what  he  actually  comprehended.  The  inferences  deduc- 
ible  from  that,  is  quite  another  matter. 

A  proposition  which  does  not  belong  to  any  of  the 
classes  now  considered,  requires  formal  proof.  If  it  is 
neither  a  matter  of  immediate  consciousness,  nor  one  of 
the  simple  and  ordinary  inferences  from  the  phenomena 
of  Apprehension  or  Memory,  nor  related  on  the  testi- 
mony of  a  credible  witness,  it  has  no  title  to  be  classed 
with  cognitions,  till  it  has  been  brought  within  the  bounds 
of  one  or  other  of  these  classes,  or  of  hypothetical  truths. 

§  5.  GENERAL  MODES  OF  DETERMINING  THE  VALIDITY  OF  PROOFS. — 
Direct  and  Indirect  Proofs. — Characteristics  of  each. — (1)  Means 
of  testing  Signs. — When  conclusive. — (2)  First  requisite  regarding 
Testimony. — Frequent  error  and  difficulty. — What  must  be  ascer- 
tained.— Second  requisite. — (3)  Requisite  in  the  case  of  Deduc- 
tions.— Hypothetical  cases. — Reasoning  from  Probabilities. — Req- 
uisite in  case  of  Absolute  Conclusions. — Frequent  Error. — (4)  Ar- 
guments.— Proper  course  in  cases  of  inadmissible  premises,  and  of 
modifying  or  distorting  the  truth. — Primary  premises  requisite  in 
investigations  regarding  Substances. — Certain  Sciences  not  inde- 
pendent of  experience. — Cases  where  the  investigation  of  an  argu- 
ment is  needless. — Caution. — New  premises. — Temporary  cessa- 
tion of  Attention. — General  and  partial  Abstracts. — Testing  final 
Conclusions. — Things  to  be  constantly  guarded  against. 

Proof  is  either  direct  or  indirect.  The  former  estab- 
lishes the  proposition  in  question  by  direct  means,  and 
the  latter,  by  showing  that  it  cannot  be  false,  or  by  es- 
tablishing something  inconsistent  with  any  other  suppo- 
sition. Thus,  when  it  is  shown  that  a  man  is  guilty  of  a 
crime,  by  the  testimony  of  a  witness  who  saw  him  com- 
mit it,  the  proof  is  direct;  and  when  it  is  proved  that 


SEC.  5.]  GENERAL  PRINCIPLES.  135 

another  is  innocent,  by  showing  that  he  was  at  a  great 
distance  Avhen  the  crime  was  perpetrated,  the  proof  is  in- 
direct. Both  kinds  of  proof  are  often  combined  in  an 
argument,  the  one  corroborating  the  other.  Thus,  it 
may  be  argued  that  a  proof  is  worthless,  by  demonstra- 
ting its  inconclusiveness  from  direct  analysis,  and  then  by 
showing  that  it  equally  proves  something  which  is  oth- 
erwise known  to  be  untrue. 

Either  kind  of  proof  is  conclusive,  when  it  conforms  to 
the  proper  criterions :  but  the  direct  is  usually  prefera- 
ble, because  it  is  more  concise,  more  easily  tested  and 
less  liable  to  error.  In  some  instances,  however,  indirect 
proof  is  more  satisfactory,  because  it  is  less  easily  forged, 
and  more  liable  to  detection  when  it  is  so  concocted. 

1.  In  determining  the  character  of  signs,  we  must  as- 
certain whether  they  are  not  compatible  with  the  falsity 
of  the  proposition  which  they  are  supposed  to  prove :  for 
they  frequently  establish  only  a  slight  probability.    Thus, 
certain  symptoms  are  often  assumed  as  proofs  that  a  per- 
son is  affected  with  a  particular  disease,  when  in  fact 
these  symptoms  accompany  several  other  diseases.    It  is 
only  where  the  signs  are  clear  and  unequivocal,  that  they 
are  entitled  to  be  received  as  conclusive  proofs.     If  the 
mercury  stands  unusually  high  in  the  barometer,  it  is  a 
sure  sign  that  the    atmospheric   pressure  is  unusually 
great:  but  if  we  assume  this  proves  it  will  be  fair  weath- 
er, we  go  farther  than  the  sign  warrants.     Those  cases 
where  a  phenomenon  can  be  shown  to  prove  a  conclusion 
only  by  means  of  a  chain  of  reasoning,  come  tinder  the 
head  of  deduction. 

2.  In   cases   of  testimony,  we    should'  first   ascertain 
whether  it  is  conclusive,  even  admitting  it  to  be  true : 
for  it  is  often  assumed  to  prove  a  proposition  when  it 
only  proves  something  like  it,  and  essentially  different. 
In  many  instances,  it  is  rendered  suspicious  by  our  ina- 
bility to  determine  whether  the  statement  is  not  a  doubt- 
ful inference  from  what  was  actually  apprehended,  as 
when  a  man  says  he  was  cured  of  a  certain  disease  by 
using  such  a  medicine,  when,  in  fact,  it  is  doubtful  wheth- 
er he  ever  had  the  disease,  and  still  more  doubtful  wheth- 
er the  medicine  had  any  beneficial  effect.     Unless  we 
know  the  phenomena  actually  comprehended,  the  testi- 
mony is  always  inconclusive,  except  in  those  cases  where 
there  is  no  ground  to  suspect  erroneous  inferences. 


136  INVESTIGATION  IN  GENERAL.    [CHAP.  VII. 

If  we  find  that  the  testimony  conclusively  proves  the 
point  in  question,  supposing  it  to  be  true,  we  must  next 
determine  whether  it  actually  is  so ;  and,  in  order  to  this, 
we  must  ascertain  whether  it  possesses  all  the  requisites 
of  reliable  testimony.  If  it  does,  it  proves  the  point  in 
question  :  otherwise  it  does  not. 

3.  In  order  to  render  deductions  satisfactory,  it  must 
be  ascertained  that  they  possess  the  four  characteristics 
of  valid  reasoning,  formerly  stated. 

In  hypothetical  cases,  the  primary  premises  are  some- 
times mere  suppositions ;  .and  the  only  thing  to  be  ascer- 
tained regarding  them  is,  whether  they  are  expressed  so 
clearly  and  precisely  that  there  is  no  danger  of  mistaking 
one  for  another.  If  not,  they  are  inadmissible :  for  it 
would  be  impossible  to  determine  whether  the  subse- 
quent reasoning  were  valid,  since  we  could  not  ascertain 
to  which  of  several  things  it  applied. 

Sometimes  the  primary  premises  are  only  probabilities ; 
and  the  conclusion  consequently  partakes  of  the  charac- 
ter of  its  bases.  We  reason  from  the  premises  as  if  they 
were  cognitions,  and  then  attribute  to  the  conclusions 
the  same  degree  of  probability  which,  we  believe,  per- 
tains to  its  foundations.  We  should  mark  the  degree  of 
probability  belonging  to  the  premises,  and  limit  the  con- 
clusion accordingly.  The  reasoning,  in  other  respects,  is 
tested  precisely  as  in  cases  where  the  primary  premises 
are  certain. 

In  all  cases  where  the  conclusions  require  to  be  proved 
absolutely,  and  not  merely  hypothetically,  or  as  proba- 
bilities, the  primary  premises,  besides  being  clear  and 
precise,  must  also  be  true.  This  is  to  be  ascertained  by 
observing  whether  they  belong  to  that  class  of  proposi- 
tions which  need  not  be  proved,  or  whether  satisfactory 
proof  has  been  already  obtained,  either  by  conclusive  test- 
imony, or  by  deducing  them  from  the  former  class  of 
truths.  If  the  premises  are  objectionable  in  this  respect, 
they  are  inadmissible,  since  otherwise  we  should  assume 
as  true  what  is  possibly  false,  and  thus  build  on  an  un- 
stable foundation. 

It  frequently  happens  that  the  premises  are  true  in 
one  respect,  but  not  in  the  sense  in  which  they  are  as- 
sumed. It  is  true,  in  one  sense,  for  instance,  that  "  hu- 
man testimony  is  fallacious,"  meaning  "  some  human  tes- 
timony :"  but  it  is  very  false  in  the  sense  that  "  no  hu- 


SEC.  5.]  GENERAL  PRINCIPLES.  137 

man  testimony  is  conclusive,"  which  is  the  sense  some- 
times attributed  to  it.  This  kind  of  error  is  greatly  fos- 
tered by  the  use  of  metaphorical  or  figurative  language: 
for  as  it  is  often  ambiguous,  it  admits  of  different  inter- 
pretations ;  and  those  who  employ  it  have  frequently  no 
clear  conception  of  what  they  mean,  and  slide  uncon- 
sciously from  one  signification  to  another. 

4.  In  arguments,  various  assumptions  are  generally 
made,  and  different  conclusions  are  deduced  from  them, 
in  the  first  instance,  but  all  going  to  establish  the  final 
conclusion.  Some  of  these  premises  may  be  admissible, 
and  others  not.  If  any  of  the  latter  be  an  essential  part 
of  the  argument,  this  vitiates  the  whole :  but,  in  some 
cases,  the  undue  assumption  is  immaterial.  To  which  of 
these  classes  a  premise  belongs,  can  frequently  be  determ- 
ined only  after  some  progress  has  been  made  in  the  ex- 
amination of  the  subject.  Here'  we  ought  to  proceed 
until  we  can  ascertain  Avhether  the  undue  assumption  is 
material,  in  which  case  the  whole  argument  is  worthless, 
or  whether  it  be  not  immaterial,  in  which  case  we  must 
beware  of  rejecting  the  whole  argument  as  worthless, 
which  would  be  like  inferring  that  the  main  channel  of 
a  great  river  must  be  dry,  because  we  have  found  some 
of  its  tributary  rivulets  dried  up. 

Sometimes  the  assumptions  are  partially  correct,  and 
only  exaggerations  or  modifications  of  the  truth.  Here 
we  adopt  the  same  course  as  in  the  preceding  case,  and 
observe  whether  the  subsequent  reasoning  is  supported 
by  the  real  facts,  when  stript  of  the  distortions  to  which 
they  have  been  subjected.  If  not,  the  argument  is  futile. 

In  all  legitimate  investigations  regarding  substances, 
the  primary  premises  must  consist,  at  least  in  part,  of 
comprehensions  or  inferences  from  them :  for  intuitions 
alone  teach  us  nothing  regarding  the  existence  of  such 
things,  and  hypotheses  here  serve  only  to  aid  us  in  de- 
ducing necessary  consequences.  Hence  all  attempts  to 
construct  physical  or  mental  sciences,  independently  of 
experience,  must  necessarily  fail :  for  the  reasoning  will 
either  be  inconclusive,  or  occupied  with  puerilities  and 
questions  beyond  the  reach  of  human  investigation. 

In  some  cases,  the  argument  is  known  to  be  invalid 
from  the  conclusion  being  either  self-evidently  false  or 
quite  incompatible  with  some  known  truth.  Wherever 
this  is,  in  reality,  the  case,  it  is  unnecessary  to  test  the 


138  INVESTIGATION  IN  GENERAL.   [CHAP.  VII. 

argument,  as  it  must  be  fallacious.  But  we  should  be 
cautious  in  making  such  admissions,  since  incompatibili- 
ties of  this  kind  are  sometimes  alleged  or  supposed, 
where  they  do  not  exist,  the  proposition  said  to  be  in- 
compatible being  either  false  or  not,  in  reality,  inconsist- 
ent with  the  one  in  question. 

Wherever  new  premises  are  assumed,  in  the  course  of 
an  argument,  we  should  test  their  character  like  that  of 
the  first  assumptions. 

The  attention  should  be  closely  fixed  on  the  subject, 
while  we  are  examining  an  argument :  for  if  this  Hags 
only  for  a  little  time,  we  may  then  encounter  and  fail  to 
detect,  a  fallacy  which  vitiates  the  whole.  This  is  par- 
ticularly apt  to  happen  in  examining  long  arguments ; 
and  it  is  a  good  rule,  in  such  cases,  to  stop  whenever  our 
attention  cannot  be  prevented  from  wandering  except  by 
a  strong  effort  of  the  Will,  and  not  resume  the  investi- 
gation till  we  are  able  to  do  so  with  unflagging  attention. 

In  difficult  cases,  much  aid  may  be  derived  from  writ- 
ing an  abstract  of  the  whole  argument,  omitting  all  de- 
tails of  facts,  and  inserting  only  the  essential  parts,  which 
never  occupy  a  large  space,  even  in  the  longest  argu- 
ments. This  will  enable  us  to  take  a  general  view  of  the 
argument,  and  attend  particularly  to  the  more  important 
parts.  We  are  apt  to  think  that  we  thoroughly  under- 
stand an  argument,  merely  from  reading  or  hearing  it, 
while  reducing  the  substance  of  it  to  writing  may  show 
us  that  we  do  not  rightly  understand  even  its  essential 
parts. 

Where  the  difficulty  lies  in  a  particular  part  of  an  ar- 
gument, this  alone  may  be  written  as  fully  as  its  nature 
requires.  Millions  have  been  misled  by  fallacies  which 
cannot  fail  to  be  readily  detected  by  any  person  who 
simply  writes  them  down  and  attentively  considers  them. 
But,  in  doing  this,  we  should  attend  to  every  essential 
part :  for  the  strength  of  a  fallacy  frequently  lies  in  its 
assuming  something  as  true  which  is  never  expressed, 
and  which  a  careful  consideration  will  show  to  be  false. 

If  we  find  that  a  conclusion  is  logically  established,  we 
should  then  ascertain  whether  this  is  the  proposition  in 
question.  In  order  to  this,  we  must  compare  the  one 
with  the  other,  and  ascertain  whether  they  are  virtually, 
if  not  completely,  identical.  If  so,  the  argument  is  sound : 
otherwise  it  is  worthless,  because  it  is  beside  the  subject. 


SEC.  1.]         NATUKE  AND  USES  OF  STUDY.  139 

t 

Throughout  every  investigation  of  proof,  we  must  be- 
ware of  being  misled  by  vague  or  indistinct  thoughts,  or 
by  obscure,  ambiguous,  or  unknown  expressions,  both  of 
which  are  frequent  sources  of  fallacy. 


CHAPTER  VIII. 

OF    STUDY. 

§  1 .  NATURE  AND  USES  OP  STUDY. — Knowledge  Original  and  Sec- 
ondary.— The  latter  acquired  by  Study. — Why  first  considered. — 
Its  Importance. — General  objects  of  Study. — Various  other  ad- 
vantages. 

KNOWLEDGE  is  either  original  or  secondary.  The  for- 
mer consists  of  that  which  is  acquired  without  any  direct 
assistance  from  others,  or  in  addition  to  the  previous  at- 
tainments of  mankind,  by  means  of  what  is  termed  orig- 
inal investigation :  the  latter  consists  of  that  which  has 
been  previously  acquired  by  others,  and  is  communicated 
to  us  by  means  of  some  known  signs,  the  investigation 
of  which,  for  the  purpose  of  learning  what  they  profess 
to  convey,  is  termed  study.  This  claims  our  first  atten- 
tion, because  it  is  -of  easier  acquisition,  and  we  are  sel- 
dom in  a  proper  position  to  enter  upon  original  investi- 
gations of  much  consequence,  until  we  know  what  others 
have  already  accomplished.  It  is  only  after  this  has  been 
acquired,  that  any  person  can  reasonably  hope  to  make 
important  additions  to  the  stock  of  human  attainments. 

The  knowledge  acquired  by  study  is  by  far  the  most 
important  of  our  attainments,  subsequent  to  those  of 
early  childhood,  since  the  original  acquisitions,  even  of 
the  most  gifted  and  favorably  circumstanced,  form  but 
a  very  small  fraction  of  the  whole  body  of  human  knowl- 
edge. This  holds  true  of  necessary,  as  well  as  of  contin- 
gent, truth,  as  to  the  latter  of  which  we  cannot  evidently 
go  beyond  the  bounds  of  our  personal  experience  with- 
out the  aid  of  others ;  and  although  we  might,  by  possi- 
bility, learn  much  of  the  former  by  our  own  unaided  ef- 
forts, yet,  considering  the  great  labor  and  difficulty  of 
establishing  many  of  the  conclusions,  we  cannot  expect 
to  master  much  of  the  subject  without  extraneous  aid. 

The  general  objects -of  study  are,  to  discipline  the  fac- 
ulties, form  proper  habits  of  investigation,  and  communi- 


140  STUDY.  [CHAP.  VIII. 

cate  to  the  learner  the  previous  attainments  of  mankind. 
But  it  frequently  effects  several  other  purposes.  Obscu- 
rities and  ambiguities  are  removed ;  fallacies  are  detect- 
ed ;  that  which  was  locked  up  in  an  unknown  language 
is  set  forth  in  the  vernacular ;  the  fragments  of  knowl- 
edge formerly  disconnected  and  hidden  from  the  view 
even  of  intelligent  men,  are  collected  and  made  to  illus- 
trate each  other,  so  that  we  obtain  a  more  extensive  and 
accurate  knowledge  of  the  subject  than  was  hitherto  pos- 
sessed by  any,  and  thus  we  see  various  parts  of  it  in  a 
new  light,  and  ascertain  what  is  defective  or  redundant. 
By  these  means,  study  not  only  renders  previous  attain- 
ments available,  but  it  also  prepares  the  way  for  new  dis- 
coveries and  inventions,  so  that  it  frequently  leads  to  suc- 
cess in  original  investigations. 

§  2.  SUBJECTS,  MODES  AND  GENERAL  RULES  or  STUDY. — Selection 
of  Subjects. — Order  of  Study. — Proper  course  regarding  certain 
Subjects. — Advantages  of  previously  considering  the  Objects  of 
Study. — Preliminary  Studies. — Extent  of  Study. — Three  modes  of 
Study. — Advantages  of  Written  Communications,  of  Conversation, 
and  of  Lectures. — Disadvantages  of  the  last. — Proper  course,  on 
controverted  Subjects. — Rules  regarding  Prejudices. — Meaning  of 
Terms. — Evils  of  disregarding  them. — Requisite  in  order  to  be  in- 
structed by  Language,  and  understanding  it  aright. — Advantage 
of  a  good  knowledge  of  the  Language. — Mode  of  dealing  with  Dif- 
ficulties.— Evil  of  deviations,  and  of  cramming. — Proper  course. 
— Common  mistake  of  beginners. — General  Rule  for  surmounting 
Difficulties. — Advantages  of  careful  and  thorough  Study,  and  evils 
of  the  opposite  course.  —  Testing  Statements. — Requisites  before 
receiving  an  Argument  as  Sound. — When  another  instructor  should 
be  sought. — Sources  of  information  which  should  be  used. — What 
subjects  should  be  studied  simultaneously. — Recreation. — Laws  of 
Health. — Final  reviewing. 

In  selecting  subjects  for  study,  we  should  first  attend 
to  those  which  ought,  on  account  of  their  general  import- 
ance, to  be  understood  by  all,  whatever  be  our  peculiar 
pursuits  or  tastes,  and  then  to  those  that  relate  to  our 
particular  vocation.  Both  of  these  are  frequently  stud- 
ied, to  some  extent,  under  teachers,  in  early  life.  But 
this  by  no  means  dispenses  with  independent  study,  in 
order  to  render  our  knowledge  of  them  accurate  and 
extensive.  We  may  afterwards  attend  to  those  studies 
and  investigations  to  which  we  are  led  by  our  individual 
tastes. and  circumstances.  These  ought  not  to  be  taken 
up  sooner,  lest  the  former  should  not  receive  due  atten- 
tion, and  our  attainments  be  most  extensive  on  subjects 
of  comparatively  little  importance. 


SEC.  2.]       SUBJECTS  AND  MODES  OF  STUDY.  141 

The  only  modification  requisite,  in  investigating  a 
branch  already  studied  under  a  teacher,  is,  that  we  may 
hurry  over  those  parts  which  we  already  sufficiently 
know  or  understand.  But  a  little  self-examination,  after 
really  mastering  the  subject,  will  frequently  show  us  that 
these  form  a  much  smaller  part  of  the  whole  than  we  had 
supposed,  and  that,  while  our  views  of  some  parts  were 
confused  and  erroneous,  we  were  totally  ignorant  of  oth- 
ers. 

Before  commencing  the  study  of  a  subject,  we  should 
consider  the  objects  which  are  to  be  accomplished  by 
mastering  it.  If  we  cannot  find  any  good  object,  we 
should  give  up  all  thoughts  of  studying  it :  for  if  we  do, 
the  only  results  will  probably  be,  that  we  shall  spend 
time  to  no  purpose,  and  form  a  habit  of  studying  in  a 
careless  manner,  and  roving  from  one  subject  to  anoth- 
er, without  acquiring  more  of  any  of  them  than  a  slight 
smattering,  which  only  fosters  a  groundless  conceit  of 
varied  knowledge. 

If,  on  the  other  hand,  important  objects  will  be  secured 
by  properly  studying  a  subject,  a  view  of  them  will  in- 
crease our  diligence  and  attention,  and  a  review  of  them 
will  revive  these,  when  they  begin  to  flag.  We  shall 
thus  secure  the  greatest  degree  of  attention  to  the  most 
important  subjects,  while  a  contrary  course  is  apt  to  pro- 
duce effects  precisely  the  reverse,  since  that  which  is  least 
important,  frequently  strikes  the  fancy  of  an  ignorant  per- 
son more  readily  and  powerfully  than  the  most  weighty 
subject. 

A  preliminary  requisite,  iif  many  cases,  is,  a  competent 
knowledge  of  those  branches  on  which  the  one  in  ques- 
tion is  based,  and  which  it  assumes  and  applies  as  al- 
ready known.  Thus,  we  cannot  master  Dynamical  As- 
tronomy without  a  knowledge  of  Dynamics;  nor  can  we 
acquire  a  knowledge  of  the  latter  till  we  have  studied 
Mathematics.  We  should  not- enter  upon  a  subject  till 
we  know  that  it  will  reward  our  labors,  and  we  have  ob- 
tained a  sufficient  acquaintance  with  the  other  branches 
requisite  to  successful  study :  and  when  we  have  taken 
it  up,  we  should  not  lay  it  aside  till  we  have  mastered  as 
much  of  it  as  our  circumstances  permit  or  require. 

Communications  from  others  may  be  written  or  oral^ 
and  the  latter  may  be  colloquial  OY  formed. 

Written  communications  possess  the  great  advantages 


142  STUDY.  [CHAP,  VIII. 

of  enabling  us  to  consider  any  part  as  often  and  as  delib- 
erately as  we  please,  to  compare  the  various  statements 
of  different  persons,  to  trace  carefully  every  part  of  a 
chain  of  reasoning,  and  to  make  a  correct  abstract  of  the 
whole,  a  thing  which  ought  to  be  done,  in  all  cases  of 
difficulty  and  importance.  Another  great  advantage  of 
writing  is,  that  it  enables  us  to  test  every  statement, 
without  any  risk  of  mistaking  it.  This  is  frequently  im- 
practicable in  oral  communications,  on  account  of  our  in- 
ability to  remember  the  very  words  employed. 

Conversation  is  more  lively,  and  allows  us  to  propose 
difficulties,  to  have  ambiguities  or  obscurities  removed 
directly,  and  to  make  inquiries  which  will  give  us  a  fuller 
and  more  correct  view  of  the  subject.  This  is  on  the 
supposition  that  the  instructor  understands  it  thorough- 
ly. If  he  does  not,  questioning  will  detect  his  deficien- 
cies more  readily  than  formal  lecturing,  which  possibly 
may  only  echo  another's  expressions,  that  were  misun- 
derstood by  the  speaker. 

Public  addresses  enable  a  person  to  convey  his  thoughts 
to  many  simultaneously,  while  they  unite,  in  some  de- 
gree, the  liveliness  of  conversation  with  the  precision  and 
regularity  of  written  discourse.  But  they  lack  the  means 
of  careful  examination  and  review  supplied  by  the  latter, 
and  the  advantages  of  questioning  the  instructor  afford- 
ed by  the  former,  so  that  it  is  impossible  to  master  any 
science  or  any  difficult  subject  by  this  means.  One  part 
is  apt  to  withdraw  our  attention  from  another,  which 
may  be  equally  important,  while  the  strong  sympathetic 
emotions  frequently  produced  by  the  presence  of  a  mul- 
titude, tend  in  the  same  direction.  Hence  we  wholly 
lose  much  of  what  is  said  ;  some  parts  are  forgotten,  and 
others  are  misunderstood.  Consequently  lectures  arc 
better  adapted  to  amuse,  or  rouse  emotions,  than  to  con- 
vey solid  instruction. 

On  controverted  subjects,  it  is  desirable  to  examine 
some  of  the  best  authorities  on  each  side :  for,  in  such 
cases,  men  are  apt  to  conceal  or  misrepresent,  so  that  we 
cannot  obtain  a  correct  view  of  the  subject  without  ex- 
amining both  sides.  Even  when  we  find,  as  frequently 
happens,  that  one  party  is  right,  in  the  main,  and  the  oth- 
er as  much  in  the  wrong,  an  examination  of  the  objec- 
tions and  arguments  of  the  latter  will  give  us  a  clearer 
and  more  extensive  view  of  the  whole  subject  than  we 


SEC.  2.]  GENERAL  RULES.  143 

could  obtain  by  studying  the  productions  of  one  party 
exclusively.  Truth  always  gains  by  a  close  and  candid 
examination :  for  the  more  it  is  investigated,  the  more 
certain  will  it  appear,  while  error  appears  more  baseless 
and  absurd,  the  more  closely  it  is  examined.  Hence  truth 
can  never  suffer  from  proper  investigation,  which  gener- 
ally explodes  error. 

We  must  constantly  guard  against  the  influence  of 
prejudices,  which  tends  to  make  us  overlook  several 
things  altogether  and  to  consider  the  rest  without  due 
care  and  attention.  A  little  reflection  will  generally  show 
us  the  nature  of  the  bias  against  which  we  have  to  guard  : 
and  when  the  statements  made  agree  with  our  wishes, 
we  should  be  particularly  cautious  in  receiving  them  as 
true,  without  the  most  conclusive  proof.  On  the  other 
hand,  we  must  beware  of  rejecting  as  unproved  a  state- 
ment which  conflicts  with  our  prejudices. 

We  are  apt  to  take  arguments  which  chime  in  with 
our  cherished  views  or  wishes  as  conclusive,  when  possi- 
bly they  may  be  quite  worthless,  while  we  are  equally 
disposed  to  reject,  as  fallacious,  arguments  which  mili- 
tate against  our  desires.  Hence  we  should  never  receive 
the  former  as  satisfactory,  till  we  have  tested  them  most 
rigidly,  while  we  should  never  reject  the  latter  as  incon- 
clusive, till  we  have  proof  that  they  are  so,  beyond  the 
possibility  of  a  rational  doubt.  We  can  generally  ascer- 
tain whether  we  have  done  so,  by  submitting  the  proofs 
to  intelligent  persons  whose  prejudices  run  counter  to 
our  own,  and  fairly  weighing  their  objections,  or  by  com- 
paring them  with  the  arguments  of  those  who  hold  op- 
posite views  of  the  subject. 

The  precise  significations  of  obscure,  ambiguous  or 
unknown  terms  should  be  ascertained  as  they  occur ;  for 
otherwise  our  labors  will  only  fill  our  minds  with  mis- 
conception and  error.  We  may  have  often  heard  or  read 
many  words  and  expressions  of  this  class,  without  ever 
knowing  their  real  signification ;  and  few  things  have 
tended  more  to  produce  and  perpetuate  error,  than  the 
free  employment  of  such  terms  by  writers,  and  their 
ready  acceptance  by  readers,  without  any  precise  defini- 
tions of  the  senses  in  which  they  were  employed  or  un- 
derstood. By  this  means  we  are  liable  to  think  that  we 
understand  a  subject,  when  our  actual  knowledge  of  it 
is  nearly  confined  to  a  string  of  unintelligible  or  vague 


144  STUDY.  [OnAp.VIII. 

phrases,  to  which  we  do  not  attach  any  precise  and  ac- 
curate signification,  and  we  have  hardly  ever  looked  be- 
yond the  mere  words. 

We  should  avoid  the  common  error  of  assuming  that 
a  knowledge  of  names  and  definitioss  is  tantamount  to  a 
knowledge  of  the  things  named  or  defined.  In  order  to 
understand  the  exact  import  of  terms  relating  to  phe- 
nomena, we  must  first  know,  by  our  own  experience,  the 
nature  of  their  primary  elements,  and  then  determine 
what  combination  of  these  is  denoted  by  the  particular 
term  in  question ;  and  we  must  always  consider  the  thing 
signified,  apart  from  its  name  :  otherwise  we  cannot 
rightly  understand  what  it  is,  and  our  supposed  knowl- 
edge of  the  subject  will  be  little  more  than  a  compound 
of  ignorance  and  positive  error. 

We  cannot  acquire  real  knowledge  by  means  of  terms 
whose  import  we  do  not  know :  and,  therefore,  although 
it  frequently  requires  time  and  labor  in  order  to  ascer- 
tain the  exact  and  proper  meaning  of  words,  it  ought  al- 
ways to  be  done ;  else  the  study  will  probably  mislead 
and  injure,  instead  of  enlightening  and  improving.  In 
effecting  this,  it  is  often  necessary  to  consider  the  things 
denoted,  apart  from  language,  and  then  compare  them 
with  the  usages  and  formal  definitions  of  those  who  best 
know  and  most  accurately  employ  the  terms  by  which 
they  are  expressed. 

The  student  should  possess  a  good  general  knowledge 
of  the  language  employed  by  the  person  whose  expres- 
sions he  is  studying :  otherwise  he  will  be  very  apt  to 
misunderstand  them.  He  should  not  presume  that  he 
possesses  a  competent  knowledge  of  the  language,  be- 
cause it  is  his  vernacular,  of  which  we  learn  only  the 
smaller  and  easier  part  .without  the  aid  of  regular  study. 
We  should,  therefore,  be  properly  prepared  on  this  point, 
before  commencing  the  study  of  any  subject  of  import- 
ance, in  order  that  we  may  know  what  is  said,  and  its 
real  import,  which  cannot  be  discovered  till  we  first  know 
precisely  what  it  is. 

When  the  student  meets  with  statements  and  reason- 
ings which  he  cannot  readily  understand,  he  should  con- 
sider them  deliberately,  and  compare  one  part  with  anoth- 
er. If  he  should  not  then  see  through  them,  the  difficul- 
ty should  be  reduced  to  writing:  for  this  concentrates 
the  attention,  so  that  it  sometimes  vanishes  by  the  time 


SEC.  2.]  GENERAL  RULES.  145 

it  is  written  down.  If  it  still  continue,  reference  may 
be  made  to  some  other  authority ;  and  if  this  does  not 
suffice,  it  should  be  noted,  and  reconsidered  at  some  fu- 
ture time.  A  more  extensive  acquaintance  with  the  sub- 
ject, or  a  better  frame  of  mind,  may  render  it  very  in- 
telligible. Difficulties  which  resist  our  efforts  to  master 
them,  in  the  course  of  formal  study,  frequently  disappear 
when  we  casually  think  of  them  calmly,  while  we  arc  not 
particularly  engaged  otherwise.  The  mental  vision  re- 
sembles the  physical,  in  our  sometimes  seeing  an  object 
better  by  means  of  an  indirect  glance  than  by  a  direct 
gaze. 

The  learner  is  always  liable  to  be  drawn  away  from 
his  proper  subject  to  collateral,  but  distinct,  matters 
which  it  suggests ;  and  he  must  beware  of  being  thus 
led  wholly  off  his  path,  or  spending  so  much  time  on  de- 
vious questions  as  unduly  to  retard  his  progress  towards 
his  proper  object.  Otherwise  he  will  be  apt  to  run  from 
one  subject  to  another,  and  resemble  a  traveler  who  in- 
cessantly deviates  to  the  right  and  left,  so  that  he  never 
reaches  his  journey's  end. 

We  should  not  study  longer  than  we  can  do  so  with 
steady  attention;  and  every  part  should  be  considered 
deliberately,  without  caring  whether  this  requires  more 
or  less  time.  When  a  person  hurries  impatiently  for- 
ward, anxious  only  to  finish  the  subject  as  soon  as  possi- 
ble, and  merely  crams  his  Memory  with  what  he  reads 
or  hears,  without  observing  its  character  or  bearings,  or 
even  comprehending  it  aright,  he  will  generally  accom- 
plish nothing  of  any  value,  and  only  acquire  bad  habits 
of  study.  What  is  apparently  acquired,  is  partly  misun- 
derstood and  blended  with  erroneous  views ;  things 
widely  different  are  confounded  with  each  other ;  and  the 
little  that  is  really  mastered,  will  be  soon  forgotten,  while 
the  hurried  and  irksome  process  is  apt  to  give  the  learn- 
er a  dislike  for  the  subject,  and  to  unfit  him  for  careful 
and  thorough  investigation. 

We  should  study  the  successive  parts,  deliberately  and 
attentively,  ascertain  the  exact  import  of  the  expressions, 
master  the  arguments,  observe  the  connection  between 
one  part  and  another,  and  ascertain  their  general  bear- 
ings and  relations.  We  shall  thus  avoid  the  habit  of 
careless  and  inattentive  study,  and  at  the  same  time  ob- 
tain a  good  understanding  of  the  subject  of  our  labors, 

G 


146  STUDY.  [CiiAp.  ViH, 

and  remember  permanently,  at  least  its  more  important 
parts; 

When  a  subject  is  studied  with  the  requisite  degree 
of  care  and  attention,  the  learner's  progress  is  apt  to  be 
slow  at  first,  especially  in  studying  science ;  and  he  is  in- 
clined to  think  that  it  forms  an  endless  task.  But  a  bet- 
ter acquaintance  with  it  will  dispel  this  error ;  and  he 
will  find  that  perseverance,  care  and  diligence  will  ena- 
ble him  to  surmount,  within  a  reasonable  time,  every  dif- 
ficulty which  he  encounters.  In  order  to  this,  however, 
he  must  begin  by  concentrating  his  attention  on  one 
short  and  simple  point,  and  mastering  it  before  proceed- 
ing to  the  next.  The  art  of  surmounting  difficulties  of 
study  lies  in  this,  attentively  considering  the  simple  de- 
ments separately.  However  complex  a  subject  may  be, 
it  always  consists  of  very  simple  elements,  just  as  the 
largest  book  is  made  up  of  a  few  letters,  and  the  most 
complex  machine  consists  of  a  few  simple  elementary 
structures. 

A  careful  and  thorough  method  of  study  from  the  out- 
set, is  the  quickest,  easiest  and  most  pleasant  means  of 
acquiring  a  good  knowledge  of  the  particular  subject, 
while  it  aids  us  in  forming  proper  habits  of  investiga- 
tion, whereas  a  contrary  course  not  only  prevents  us  from 
ever  acquiring  a  good  knowledge  of  that  subject,  but 
also,  by  fostering  habits  of  hasty  and  careless  investiga- 
tion, tends  to  keep  us  ignorant  on  other  subjects.  It 
leads  us  to  adopt  the  errors  of  others,  and  add  many  of 
our  own. 

Those  who  skim  along  the  surface,  or  run  from  one 
study  to  another,  without  rightly  finishing  any,  can  ac- 
quire a  good  knowledge  of  none  of  them,  while  the  bad 
habits  they  form,  become  inveterate.  In  order  to  mas- 
ter the  subject,  train  the  intellect  aright,  and  form  prop- 
er habits,  the  student  must  proceed  deliberately,  and 
avoid  hurry  and  superficial  work.  These  lead  to  time 
being  lost  in  acquiring  narrow  and  erroneous  views, 
which  must  be  unlearned  before  he  can  acquire  an  accu- 
rate knowledge  of  the  subject ;  and  this  now  becomes 
more  disagreeable  than  at  the  first,  because  it  has  lost 
the  charms  of  novelty. 

The  statements  and  reasonings  should  be  tested  by 
the  proper  criterions,  as  they  occur.  Thus,  when  as- 
sumptions are  made,  on  the  authority  of  Consciousness, 


SEC.  2.]  GENERAL  RULES.  ]47 

we  should  observe  whether  they  are  really  discernments ; 
where  statements  are  made  on  testimony,  we  should  try 
whether  it  is  satisfactory ;  where  a  conclusion  is  inferred 
from  certain  premises,  or  held  to  have  been  already  le- 
gitimately established,  we  should  examine  whether  this 
is  actually  the  case ;  and  where  a  conclusion  is  logically 
proved,  we  should  ascertain  whether  it  is  the  real  point 
in  question,  or  the  one  which  ought  to  have  been  proved. 

Our  inability  to  detect  a  fallacy  should  never  lead  us 
to  receive  an  argument  as  sound,  unless  every  essential 
part  is  found,  upon  proper  examination,  to  accord  with 
the  criterions  of  truth.  We  are  not  warranted  in  assum- 
ing that  it  is  sound,  simply  because  we  do  not  see  that  it 
is  otherwise ;  and  the  proper  course  is,  to  assume  that 
everything  is  fallacious,  for  the  truth  or  correctness  of 
which  we  have  not  the  evidence  of  Consciousness,  at 
every  step,  and  in  every  part :  otherwise  we  shall  fre- 
quently adopt  gross  error  as  demonstrated  truth.  For 
the  most  pernicious  errors  can  be  sustained  by  plausible 
arguments,  which  sound  and  look  well,  and  whose  real 
character  cannot  be  detected  without  a  close  and  atten- 
tive examination.  Some  attempt  to  avail  themselves 
safely  of  others'  labors,  by  simply  adopting  their  conclu- 
sions, without  any  proper  examination  of  their  argu- 
ments :  but  this  course  is  always  liable  to  mislead ;  and 
it  has  very  frequently  led  to  the  adoption  of  the  most 
pernicious  errors. 

The  best  accessible  sources  of  information  should  al- 
ways be  used;  and  the  student  should  never  rest  satis- 
fied with  a  doubtful  authority,  when  he  can  consult  one 
which  is  unquestionable.  Thus,  he  should  not  take  sec- 
ond-hand accounts  of  an  author's  doctrines,  when. he  can 
consult  his  own  writings ;  a  prevaricator  should  not  be 
listened  to,  where  a  person  of  strict  veracity  testifies  on 
the  point ;  and  he  should  not  pay  any  regard  to  hearsay 
or  flying  rumors,  when  he  may  obtain  the  statements  of 
a  credible  eye-witness.  So,  he  should  not  employ  a  teach- 
er who  expresses  himself  vaguely,  obscurely  or  unintelli- 
gibly, reasons  fallaciously,  or  arranges  his  materials  con- 
fusedly, when  he  may  have  recourse  to  .another  who  is 
free  from  such  defects,  and  in  no  important  respect  infe- 
rior. 

We  should  never  study  at  a  time  more  than  one  sub- 
ject requiring  close  and  deep  thinking,  since  otherwise 


148  STUDY.  [CHAP.VIIL 

we  cannot  devote  the  requisite  degree  of  attention  to 
each,  because  they  have  a  tendency  to  draw  the  atten- 
tion to  themselves,  even  when  we  are  engaged  with  other 
matters.  But  such  studies  should  be  intermingled  with 
those  which  entertain  the  mind,  without  seriously  im- 
pairing its  energies. 

Study  should  be  diversified,  at  moderate  intervals,  with 
pursuits  requiring  active,  but  not  toilsome  muscular  ex- 
ercise, and  forming  an  agreeable  relaxation  for  the  mind : 
otherwise  what  is  learned  is  apt  to  be  mastered  imper- 
fectly, and  speedily  forgotten. 

The  student  will  be  quickly  incapacitated  for  success- 
ful efforts,  unless  he  attends  to  the  laws  of  health,  and 
avoids  deleterious  agencies  and  practices  :  for  disease  not 
only  injures  the  senses,  and  the  power  of  accurate  observ- 
ation or  continued  application,  but  it  also  distracts  the 
attention  and  impairs  the  Memory,  so  that  it  generally 
renders  successful  study  impracticable. 

Before  finally  discontinuing  the  study  of  a  subject,  the 
whole  should  be  reviewed  mentally,  and  reference  made 
to  a  teacher  or  a  book  only  when  we  are  at  a  loss.  The 
foundations,  scope  and  connections  of  the  various  parts 
should  be  considered,  until  we  clearly  understand  and  re- 
member them.  We  should  also  ascertain  what  properly 
belongs  to  the  subject,  mark  the  parts  of  which  our 
knowledge  is  defective,  and  rightly  employ  the  best  means 
within  our  reach  for  supplying  the  deficiency.  Without 
some  such  course  as  this,  it  is  generally  impossible  for 
most  persons  to  possess  a  good  and  extensive  knowledge 
of  the  subject,  or  to  see  the  amount  of  their  real  attain- 
ments. We  are  often  apt  to  think  that  we  know  a  sub- 
ject well,  when  this  process  will  show  us  the  contrary, 
and  convince  us  that  our  knowledge  of  it  is  much  less 
extensive  and  accurate  than  we  supposed. 

§  3.  SELECTION  AND  STUDY  OF  BOOKS. — Great  Importance  of  Writ- 
ings.— No  privileged  road  to  valuable  Knowledge. — Means  of  dis- 
covering good  and  detecting  bad  Books. — Characteristics  of  the 
best  works  for  Beginners. — Two  evil  Practices. 

In  every  study  of  any  extent,  we  require  the  aid  of 
written  or  printed  materials,  in  order  to  understand  the 
statements  aright,  and  impress  them  on  the  Memory,  and 
also  to  follow  the  chains  of  argument,  and  test  their  va- 
lidity. To  be  convinced  of  this,  we  need  only  consider 


SEC.  3.]  BOOKS.  149 

the  extreme  difficulty  of  remembering  the  substance  of 
a  discourse,  after  one  hearing,  or  following  an  ordinary 
mathematical  demonstration,  without  the  assistance  of 
visible  words  and  symbols. 

There  is  no  privileged  easy  road  to  valuable  knowledge 
of  any  kind.  It  is  not  enough  to  sit  down  and  passively 
read  or  listen  to  the  words  of  a  teacher :  we  must  act- 
ively attend  to  what  is  said,  test  it  properly,  and  commit 
more  or  less  of  it  to  Memory.  The  best  teacher  can  only 
assist  the  learner :  the  subject  must  be  mastered,  and  the 
chief  difficulties  surmounted,  by  his  own  individual  ef- 
forts. Hence  the  necessity  of  having  recourse  to  books, 
in  order  to  obtain  a  correct  knowledge  of  any  subject. 

On  most  subjects  of  importance,  numerous  works  have 
been  published,  of  very  different  degrees  of  merit.  Some 
are  of  such  a  character  that  time  spent  in  studying  them 
would  be  thrown  away ;  and  even  where  several  are 
good,  one  may  be  much  better  than  any  of  the  rest. 
Hence  care  should  be  taken  to  procure  the  best:  and,  for 
this  purpose,  the  advice  of  judicious  persons  well  ac- 
quainted with  the  subject  and  its  literature,  is  of  great 
service.  But  we  must  beware  of  regarding  the  opinion 
of  a  distinguished  man,  on  a  subject  with  which  he  is  not 
well  acquainted.  A  great  chemist  may  be  a  bad  guide 
in  Mathematics ;  and  one  well  skilled  in  Elementary  Ge- 
ometry may  know  very  little  of  Mathematical  Analysis. 

It  is  equally  requisite  to  ascertain  whether  the  person 
to  whom  we  apply  is  not  under  the  influence  of  strong 
personal,  party  or  national  prejudices,  which  may  render 
his  opinion  unreliable.  The  opinions  of  anonymous  and 
unknown  critics  cannot  be  safely  followed,  because  they 
may  really  know  little  of  the  subject,  or  be  influenced  by 
strong  prejudices  or  sinister  motives. 

In  the  absence  of  any  reliable  advice  from  others,  we 
may  frequently  detect  a  worthless  book  by  certain  char- 
acteristic marks.  Sometimes  the  very  title  shows  that 
the  writer  knows  little  of  the  subject,  as  where  it  prom- 
ises a  refutation  of  the  Copernican  system  of  Astrono- 
my, or  a  disclosure  of  the  means  of  living  as  long  as  we 
please,  or  of  constructing  machines  that  can  be  moved 
by  weights  without  ever  being  wound  up.  Occasionally 
the  author  evidently  commits  a  fatal  error  at  the  outset, . 
such  as  assuming,  in  effect,  the  very  thing  he  professes 
to  prove,  or  attempting  to  prove  something  self-evidently 


150  STUDY.  [CHAP.  VIII. 

impossible.  In  other  instances,  he  expresses  himself  in 
such  a  manner  that  we  cannot  discover  his  meaning,  on 
fundamental  or  material  points. 

In  many  cases,  the  character  of  a  book  may  be  discov- 
ered by  special  tests.  Thus,  the  impartiality  of  an  histo- 
rian may  be  tried  by  observing  how  he  handles  a  sub- 
ject with  which  we  happen  to  be  well  acquainted,  just 
as  we  test  the  accuracy  of  an  Atlas,  by  looking  at  the 
representations  of  parts  with  which  we  are  familiar.  So, 
the  reasoning  powers  and  ingenuity  of  an  author  may  be 
ascertained,  by  observing  how  he  discusses  some  point 
of  peculiar  difficulty ;  and,  in  the  same  way,  we  can  often 
determine  whether  he  is  credulous  or  sceptical,  indolent 
or  industrious,4earned  or  ignorant,  modest  or  conceited, 
loose  or  precise  in  his  statements,  and  so  forth. 

On  first  beginning  the  study  of  a  subject,  we  should, 
if  possible,  choose  a  work  which  avoids  the  dryness  of 
brief  outlines,  on  the  one  hand,  and  tedious  details  and 
discussions  on  the  other.  The  former  are  generally  un- 
interesting for  their  meagerness,  and  frequently  substi- 
tute the  shadow  for  the  substance,  while  the  latter  weary 
a  beginner  by  their  prolixity.  The  best  book  for  a  be- 
ginner is,  one  which  goes  systematically  over  the  whole 
ground,  and  refers  to  no  other  source  for  rudimentary 
instruction,  which  is  fair  and  accurate  in  its  statements, 
sound  in  argument,  clear  and  precise  in  style,  and  which 
exhibits  the  subject  in  its  most  improved  form,  without 
omitting  anything  of  great  importance  which  falls  with- 
in its  scope. 

Having  selected  a  text-book,  we  should  confine  our  at- 
tention to  it,  till  we  have  perused  and  understood  it,  ex- 
cept where  we  meet  with  some  difficulty  which  resists 
our  best  efforts  to  surmount  it,  or  some  defect  which  must 
be  supplied  from  another  source.  Flying  from  one  treat- 
ise to  another  distracts  the  attention,  and  is  apt  to  pro- 
duce erroneous  views  of  the  subject.  But,  after  proper- 
ly finishing  one  good  general  treatise,  we  may  advan- 
tageously consult  other  works,  which  contain  views  or 
matter  not  found  in  the  former.  Our  previous  attain- 
ments will  render  it  unnecessary  to  do  more  than  run 
over  these  productions,  and  attend  chiefly  to  what  is  new 
to  us. 

We  should  avoid  the  pernicious  custom  of  running 
from  one  part  of  a  book  to  another,  and  not  studying  it 


SEC.  1.]  GENERAL  CHARACTER,  &c.  151 

continuously  from  the  beginning,  which  is  the  proper 
method.  What  precedes,  is  generally  the  foundation  of 
what  follows,  especially  in  scientific  works  Hence  we 
cannot  rightly  understand  the  subject,  unless  we  peruse 
the  book  in  regular  order;  and  even  the  little  that  we 
do  learn,  is  so  disconnected  that  it  is  mostly  forgotten, 
after  a  short  interval. 


CHAPTER  IX. 

OF    ORIGINAL   INVESTIGATION. 

§  1.  GENERAL  CHARACTER,  USER,  PREREQUISITES,  AND  METHODS  or 
ORIGINAL  INVESTIGATION. — Why  Original  Inw3stigation  is  more 
difficult  than  Study. — How  it  differs  from  Study. — Why  its  fields 
are  gradually  narrowing. — Advantages  of  original  Researches  and 
new  Discoveries.  —  Superiority  of  personal  Observations.  — Why 
those  of  others  should  not  be  overlooked. — Relation  of  the  preced- 
ing to  the  present  subject. — Means  of  selecting  subjects. — Seven 
Prerequisites,  and  remarks. — Two  methods  of  proceeding. — Subdi- 
vision.— Six  Rules  regarding  the  course  of  proceeding. 

ORIGINAL  investigation  presents  greater  difficulties 
than  study,  because  it  is  more  indefinite.  While  we 
consider  only  cognitions,  we  may  easily  know  the  pre- 
cise thing  to  be  done  :  but  when  we  enter  on  the  region 
of  the  unknown,  we  are  often  at  a  loss  which  way  to  di- 
rect our  course.  In  study,  words  and  direct  representa- 
tions guide  us  to  the  knowledge  of  the  things  in  ques- 
tion :  but  here  we  should  begin  with  the  latter,  and  end 
with  the  former,  which  should  not  be  employed  till  we 
know  the  precise  thing  which  we  denote  by  them  ;  and 
when  that  is  done,  we  should  write  this  down,  wherever 
there  is  any  danger  of  our  afterwards  forgetting  or  mis- 
taking it. 

While  the  fields  of  study  are  becoming  more  extensive, 
as  time  adds  to  the  truths  already  known,  those  of  orig- 
inal research  are  becoming  gradually  narrower,  not  only 
because  less  remains  to  be  discovered,  but  because  new 
additions  to  the  stock  of  knowledge  frequently  render  it 
more  difficult  to  place  ourselves  on  the  vantage  ground 
for  making  further  additions.  Yet  mankind  are  far  from 
having  reached  the  boundaries  of  possible  attainments ; 
and  if  new  discoveries  increase  the  preliminary  labors  of 
subsequent  explorers,  new  inventions  may  aid  them  in  a 


152  ORIGINAL  INVESTIGATION.        [CiiAP.  IX. 

corresponding  degree,  while  the  wider  generalizations 
and  more  compact  and  regular  arrangement  of  materials, 
resulting  from  increased  knowledge,  frequently  facilitate 
future  acquisitions  more  than  this  difficulty  retards  them. 
When  the  materials  are  confusedly  arranged,  and  con- 
sist of  unconnected  fragments,  intermixed  with  many 
errors  and  redundancies,  as  is  often  the  case  in  the  earlier 
stages  of  a  science,  it  may  require  more  time  to  learn 
the  little  that  is  known,  than  it  will  take  to  master  the 
whole,  after  original  investigations  have  given  it  a  more 
regular  and  connected  form,  and  banished  the  crude 
speculations,  positive  errors,  and  prolix  irrelevancies  of 
its  rudimentary  stages. 

Original  researches  or  observations  are  evidently  the 
only  means  of  making  additions  to  the  sum  of  human 
knowledge,  or  discovering  something  that  nobody  knew 
before.  They  also  detect  errors,  or  confirm  previous  re- 
searches, even  when  they  fail  to  make  any  such  additions. 
Many  instances  occur,  in  the  history  of  science,  where 
tilings  assumed  for  ages,  as  established  inductions,  were 
found,  by  subsequent  research,  to  be  totally  erroneous. 
Of  this  the  old  opinion  regarding  the  influence  of  the 
Moon  on  the  weather  and  vegetation,  is  a  good  in- 
stance. 

In  other  cases  a  proposition,  true  in  the  main,  may  be 
found  to  have  been  either  too  wide  or  too  narrow,  or  to 
have  involved  some  degree  of  positive  error.  It  is  also 
no  small  advantage  that  disputed  points  should  be  estab- 
lished, by  an  irresistible  mass  of  evidence,  beyond  further 
cavil  or  contradiction,  from  any  person  who  has  proper- 
ly examined  the  subject,  even  although  the  matter  in 
question  may  have  been  virtually  established  before. 

Original  observation  also  gives  us,  in  many  cases,  a 
more  lively  impression  and  more  exact  knowledge  of 
things,  than  we  could  obtain  from  descriptions,  as  Con- 
ception is  more  feeble  than  Apprehension,  and  at  the 
same  time  more  liable  to  mislead  us,  to  say  nothing  of 
the  numerous  mistakes  arising  from  language.  But  we 
should  not  forget,  on  the  other  hand,  that  a  person  well 
acquainted  with  the  whole  subject,  may  give  us  a  more 
extensive  and  accurate  knowledge  of  it  than  we  could 
acquire  by  our  own  unaided  observation.  We  should, 
therefore,  never  fail  to  examine  the  statements  of  other 
intelligent  men  who  have  examined  the  same  objects. 


SEC.  1.]  PREREQUISITES.  153 

They  will  generally  furnish  important  aid  towards  a  good 
understanding  of  them. 

What  was  said,  in  the  preceding  chapter,  regarding 
the  number  of  subjects  that  should  engage  our  attention 
at  one  time,  the  propriety  of  exercise  and  relaxation,  and 
observing  the  laws  of  health,  are  equally  applicable  to 
the  subject  of  the  present ;  and,  in  the  higher  depart- 
ments of  original  research,  a  careful  attention  to  them  is 
still  more  requisite,  since  the  mind  is  more  absorbed,  and 
the  physical  energies  more  prostrated  than  when  we  are 
only  following  in  the  footsteps  of  others.  Here  vigorous 
thinking  is  generally  requisite  to  success,  since  feeble  and 
superficial  eiforts  will  accomplish  nothing  of  consequence, 
though  continued  for  years. 

Few  persons  will  care  to  turn  their  attention  to  every- 
thing worthy  of  investigation ;  and  knowledge  is  best 
advanced  by  every  one's  attending  to  what  most  inter- 
ests him,  as  this  is  generally  the  subject  to  which  his  pre- 
vious pursuits  and  attainments  qualify  him  to  do  justice. 
In  selecting  subjects,  the  best  course  generally  is,  to  take 
up  those  which  we  can  investigate  with  the  greatest 
zeal  and  perseverance  ;  for  unless  we  delight  in  the  pur- 
suit, our  labors  will  generally  prove  abortive. 

The  following  are  the  principal  requisites  preliminary 
to  original  investigation. 

1.  The  mental  and  bodily  facilities  requisite  to  success 
in  the  particular  department  of  investigation.     A  blind 
man  cannot  extend  the  science  of  Optic,  nor  a  deaf  man 
that  of  Acoustic.     So,  one  who  is  unable  to  reason  accu- 
rately and  continuously,  should  not  attempt  new  discov- 
eries in  Mathematics;  nor  should  one  who  is  unable  to 
analyse  thought,  attempt  to  extend  mental  science.     We 
should  possess  those  talents  which  are  indispensable  to 
success,  before  attempting  any  original  investigation : 
otherwise  we  shall  labor  in  vain. 

2.  A  precise  and  accurate  conception  of  the  very  thing 
of  which  we  are  in  search.     Unless  we  determine  this, 
we  must  work,  in  a  great  measure,  at  random,  and  spend 
our  time  and  labor  without  knowing  the  exact  object  of 
our  pursuits,  so  that  we  shall  generally  effect  nothing  of 
any  consequence. 

3.  A  subject  worthy  of  our  investigation,  and  within 
the  reach  of  the  human  faculties.     Otherwise  we  shall 
pursue  trifles,  or  attempt  impossibilities,  and  our  efforts 

G  2 


154  ORIGINAL  INVESTIGATION.       [CHAP.  IX. 

will  prove  abortive.  The  difficulty  of  a  subject  is  no  cri- 
terion of  its  value.  It  is  harder  to  chew  the  shells  than 
the  kernels;  yet  the  latter  are  by  far  the  more  nutri- 
tious ;  and  the  case  is  frequently  the  same  with  knowl- 
edge. That  which  is  obtained  with  most  difficulty,  may 
possibly  be  the  least  valuable. 

4.  A  knowledge  of  previous  attainments  regarding  the 
subject  of  investigation.    Unless  we  know  what  has  been 
already  accomplished  by  others,  we  may  toil  in  repeating 
what  others  previously  achieved. 

5.  An  acquaintance  with  the  various  branches  of 
knowledge  which  are  related  to  the  subject  of  examina- 
tion.    Otherwise  we  lack  a  good  guide  to  direct  our  in- 
vestigations, since  one  department  always  throws  light 
on  kindred  subjects. 

6.  A  knowledge  of  the  history  of  that  branch  to  which 
the  subject  under  consideration  belongs.     This  will  pre- 
vent us  from  attempting  what  has  already  been  found  to 
be  impracticable,  and  at  the  same  time  furnish  various 
hints  regarding  the  best  mode  of  proceeding. 

7.  Any  instruments,  tools,  or  apparatus  which  may  be 
requisite  in  investigating  the  subject.     No  progress  can 
be  made  in  astronomical  observations  without  telescopes, 
accurate  time -keepers,  and  instruments  for  measuring 
small  angles.     So,  the  chemist  requires  retorts,  heat,  and 
reagents.     Indeed  most  of  the  physical  sciences  require 
some   apparatus  in  order  to  extend  their  boundaries, 
without  which  success  cannot  reasonably  be  expected. 

In  making  original  investigations,  we  may  proceed  by 
two  different  methods:  1.  We  may  simply  observe  and 
record  phenomena,  including  immediate  and  obvious  in- 
ferences, as  when  we  travel  through  a  foreign  country, 
and  learn  its  geography,  or  discover  new  species  of  plants 
and  animals.  This  method  may  be  termed  direct  inves- 
tigation. 2.  We  may  commence  with  discernments,  as- 
sumptions, or  the  truths  acquired  by  the  preceding  meth- 
od, and  proceed  to  trace  latent  causes  or  remote  conse- 
quences and  inferences,  forming  indirect  investigation. 
Such  are,  the  discovery  of  the  real  motions  of  the  Earth 
and  the  invention  of  a  calculating  machine.  Here  it  is 
frequently  requisite  to  employ  long  chains  of  reasoning, 
and  hypotheses,  or  experiments.  This  method  may  be 
subdivided  into — indirect  discovery,  where  we  ascertain 
new  truths  otherwise  than  by  direct  discovery — and  in- 


SEC.  2.]  PBINCIPAL  RULES.  155 

mention,  where  we  contrive  a  new  combination,  or  devise 
some  new  means,  for  effecting  a  definite  object  or  known 
end. 

The  following  are  the  principal  rules  applicable  to  both 
methods : 

1.  Obtain  clear  and  distinct  comprehensions,  so  that 
you  may  know  the  exact  thing  comprehended,  and  dis- 
tinguish it  from  any  other  which  it  may  resemble :  else 
your  knowledge  of  the  subject  will  be  vague  and  dim,  or 
you  will  mistake  one  thing  for  another. 

2.  Obtain  complete  comprehensions ;  otherwise  you 
will  think  that  you  understand  the  whole  subject,  when 
you  see  only  one  side  of  it ;  and  serious  error  will  result. 
In  order  to  this,  we  must  look  closely  to  every  part  of 
the  subject,  and  not  turn  away  from  anything  because  it 
may  be  displeasing. 

3.  Distinguish  probability  from  certainty,  and  draw 
no  inferences  but  such  as  necessarily  follow  from  your 
comprehensions:  for  otherwise  you  w'ill  inevitably  fall 
into  error. 

4.  If  you  form  hypotheses,  test  them  by  the  proper  rules 
for  that  purpose,  that  an  erroneous  hypothesis  may  not 
be  substituted  for  a  demonstrated  theory. 

5.  In  classifying  your  knowledge,  adhere  to  the  princi- 
ples of  classification,  so  that  you  may  avoid  the  confu- 
sion which  will  otherwise  ensue. 

6.  Write  down  properly ,  and  with  the  least  possible  de- 
lay, the  results  of  your  labors,  so  that  you  may  avoid  er- 
rors of  memory.     When  some  interval  has  elapsed,  pre- 
vious to  writing,  it  should  be  noted ;  and  we  should  em- 
ploy the  most  appropriate  terms  for  expressing  those  re- 
sults. 

•  2.  OP  DIRECT  DISCOVERY. — Requisites  to  Success. — Common  Er- 
rors.— Proper  Course. — Important  requisite,  in  certain  Investiga- 
tions.— Sphere  of  Direct  Discovery. 

This  kind  of  investigation  requires  sound  senses,  care- 
ful observation,  and  an  application  of  .the  simpler  proc- 
esses of  generalization,  with  sufficient  judgement  to  direct 
the  mind  to  proper  objects.  It  is  also  necessary  to  pos- 
sess habits  of  close  attention,  and  of  distinguishing  phe- 
nomena from  inferences  or  conceptions,  so  that  one  thing 
may  not  be  mistaken  for  another,  and  what  is  actually 
seen  confounded  with  what  is  only  inferred  or  imagined. 


156  ORIGINAL  INVESTIGATION.       [CHAP.  IX. 

To  guard  against  such  errors,  we  must  use  the  means 
formerly  pointed  out,  for  determining  what  is  really  com- 
prehended, and  what  are  the  direct  legitimate  inferences. 

In  all  investigations  in  the  physical  and  mental  sci- 
ences, we  must  beware  of  the  once  common  practice  of 
assuming  that  things  are  as  we  think  they  must  or  ought 
to  be,  instead  of  ascertaining  how  they  actually  are,  which 
may  differ  widely  from  the  former.  We  are  tempted  to 
this  course  by  the  comparative  ease  with  which  disputed 
or  doubtful  points  may  thus  be  apparently  set  attest. 
Another  common  error  is,  to  gather  up  all  that  leads  to 
a  favorite  conclusion,  and  overlook  everything  of  a  con- 
trary tendency,  which  may  possibly  be  more  cogent  than 
the  former. 

We  should  observe  closely  and  attentively  all  that  is 
within  our  reach  which  has  a  bearing  on  the  subject,  so 
as  neither  to  overlook  anything  of  importance,  nor  dis- 
tinguish things  that  are  essentially  alike,  or  confound 
things  that  are  otherwise :  we  should  record  clearly  and 
accurately,  with  the  least  possible  delay,  what  admits  of 
description  and  is  liable  to  be  forgotten :  and  we  should 
draw  no  unwarrantable  inferences.  In  order  to  avoid 
misdescription,  we  must  rightly  understand  the  thing  to 
be  described,  and  employ  suitable  terms  for  that  purpose. 
Where  we  have  failed  to  make  a  record  at  the  time  of 
observation,  we  should  beware  of  stating  more  than  we 
distinctly  remember,  and  note  the  interval  between  the 
time  of  observing  and  writing :  otherwise  various  errors 
will  probably  ensue. 

In  those  investigations  which  involve  quantity  as  a 
material  element,  exact  numerations  or  measurements 
are  of  much  importance,  in  enabling  us  to  avoid  error. 
Many  false  theories,  adopted  for  centuries,  w^ould  have 
been  at  once  exploded  by  the  application  of  this  test. 

Although  unexplored  regions  or  subjects  furnish  the 
widest  fields  for  direct  discovery,  yet  there  is  often  am- 
ple room  for  them  elsewhere ;  and  much  that  is  unknown 
and  important  may  often  be  learned  from  proper  observ- 
ations, made  in  places  often  traversed,  but  never  thor- 
oughly explored,  or  on  subjects  often  considered,  but 
never  thoroughly  understood. 

§  3.  OF  INDIRECT  DISCOVERY.— Requisites  to  Success. -—Principal 
Fields. — Uses  of  a  knowledge  of  kindred  departments. — How  prop- 
er Subjects  are  discovered. — Next  Step. — Extension  of  Gcncrnlizn- 


SEC.  3.]  INDIRECT  Disco  VKIIY.  157 

tion. — Analogy. — Proper  Course  regarding  it. — Its  Uses. — Abuse 
of  Analogies. — Usual  course  of  Indirect  Discovery. — Importance 
and  means  of  readily  discovering  the  most  probable  Hypothesis. — 
Indications  of  such  Hypotheses. — Usual  results,  where  no  Proba- 
bility guides-the  investigation. — How  to  be  avoided. — Importance 
of  analysing  the  subject  mentally. — What  is  frequently  the  great- 
est Difficulty. — Means  of  effecting  the  Analysis. — Mode  of  proceed- 
ing where  we  cannot  employ  Premises  strictly  True. — Failures. — 
Mode  of  proceeding  where  there  are  several"  Independent  Means 
of  testing  the  Conclusion. — Rules  regarding  Experiments. — Prob- 
able Consequences  of  disregarding  them. — Requisites  before  draw- 
ing a  final  Conclusion.  • 
In  addition  to  the  prerequisites  mentioned  in  the  pre- 
ceding section,  the  successful  prosecution  of  this  kind  of 
discovery  requires  that  the  faculties  of  Intuition  and  Con- 
ception should  be  vigorous,  and  that  the  investigator 
should  possess  great  perseverance  and  the  power  of  con- 
tinued attention.     Activity  of  conception  will  produce 
only  wild  theories,  unless  its  operations  are  controlled  by 
close  reasoning,  and  its  productions  tested  by  careful  ob- 
servation or  experiment.    Acuteness  of  apprehension  and 
a  strong  memory  are  advantageous  ;  but  they  are  not  in- 
dispensable. 

The  principal  fields  of  indirect  research  are,  the  sciences 
and  the  arts.  The  former  are  so  connected  that,  in  or- 
der to  be  placed  in  a  favorable  position  for  extending 
their  boundaries,  the  investigator  should  possess  a  knowl- 
edge of  the  elements  of  all  that  have  a  bearing  on  his 
immediate  subject,  in  order  that  the  various  things  which 
must  be  considered,-  may  suggest  themselves  to  his  mind 
at  the  proper  time.  This  requires  that  he  familiarize 
himself  with  them,  by  repeatedly  considering  them  close- 
ly and  attentively. 

The  investigator  should  also  be  well  acquainted  with 
the  various  parts  of  the  subject,  as  it  now  stands,  and 
able  to  view  them  in  all  their  principal  relations ;  for  a 
knowledge  of  one  part  is  often  necessary  to  a  right  un- 
derstanding of  another,  apparently  unconnected  with  it. 
It  is  only  by  means  of  the  known  that  we  ascertain 
the  unknown :  and,  therefore,  a  knowledge  of  the  way  in 
which  former  discoveries  were  made,  of  the  suggestions 
thrown  out  by  their  authors,  and  of  the  failures  that  oc- 
curred, generally  furnishes  indications  of  the  means  by 
which  a  doubtful  or  disputed  point  can  be  either  estab- 
lished or  disproved,  while  it  guards  us  against  courses 
which  are  likely  to  prove  unavailing. 


158  ORIGINAL  INVESTIGATION.        [CHAP.  IX. 

Proper  subjects  for  investigation  are  suggested  by  the 
deficiencies  of  some  science  or  art,  or  the  manifest  ad- 
vantages of  further  knowledge,  on  some  point  regarding 
which  little  is  still  known. 

The  next  thing  is,  to  ascertain  the  limits  within  which 
the  proofs  are  likely  to  be  found ;  and  here  the  subject 
itself  generally  indicates  their  source,  as  they  are  usual- 
ly found  in  other  parts  of  it,  or  in  kindred  branches  of 
knowledge. 

Some  of  the  most  important  additions  to  knowledge 
consist  of  the  extension  of  generalization,  or  of  bringing 
a  certain  law  under  a  superior  law.  In  effecting  this,  we 
are  often  aided  by  analogy,  which  is,  a  resemblance  tran- 
scending direct  apprehension,  such  as  similarity  of  func- 
tions, origin,  tendency,  or  any  other  relation.  Visible  re- 
semblances have  seldom  a  place  in  these  investigations, 
because  they  are  exhausted  in  forming  the  lower  gener- 
alizations. 

In  searching  either  for  analogies  or  closer  resemblances, 
we  should  first  refer  to  those  things  which  most  resem- 
ble the  one  under  consideration,  as  these  are  most  likely 
to  furnish  faithful  similarities.  It  is  proper  afterwards 
to  extend  our  comparisons,  in  order  to  reach  the  higher 
generalizations,  or  remove  doubts  or  difficulties.  Thus, 
some  obscure  points  in  Physiology  have  been  cleared  up 
by  having  recourse  to  Phy tology,  or  that  part  of  Botany 
which  treats  of  vegetable  structures. 

The  reality  of  supposed  analogies  is  to  be  tested  by 
observations  or  experiments ;  and  the  nature  of  those  re- 
quired is  generally  indicated  by  the  analogy:  but  the 
proper  mode  of  conducting  them  often  requires  great 
skill  and  dexterity,  which  is  obtained  only  by  some  prac- 
tice and  a  good  acquaintance  with  the  general  subject. 

The  discovery  of  mere  analogies  is  sometimes  a  thing 
of  great  importance  as  an  end,  since  they  furnish  proba- 
bilities, which  are  all  that  require  to  be  known,  in  many 
cases.  But  they  are  more  frequently  important  as  a 
means  of  extending  generalization :  for,  by  discovering 
such  resemblances,  we  are  often  led  to  find  that  things 
apparently  very  different,  are  still  of  the  same  class.  The 
polarity  of  a  magnetic  needle  has  no  apparent  resem- 
blance to  the  phenomena  of  common  electricity;  yet, 
when  we  observe  that  the  like  poles  attract,  and  the  un- 
like repel,  each  other,  as  in  the  case  of  two  excited  elec- 


SEC.  3.]  INDIRECT  DISCOVERY.  159 

tries,  we  might  suspect  that  botli  phenomena  belong  to 
one  general  class,  a  conjecture  which  has  been  fully 
established. 

Analogies  also  guide  us  in  testing  hypotheses :  for  as 
every  analogy  furnishes  a  probability  of  the  truth  of  the 
hypothesis  based  on  it,  the  closest  and  most  numerous 
analogies  indicate  the  most  probable  hypotheses,  and 
thus  aid  us  in  ascertaining  the  tvuth. 

Analogies  are  very  liable  to  produce  a  belief  that  the 
resemblances  extend  farther  than  they  really  do,  and  that 
resemblance  in  one  thing  proves  a  like  resemblance  in 
another,  or  that  things  which  perform  similar  functions 
are  themselves  similar.  They  have  thus  led  to  various 
errors :  and,  therefore,  we  should  note  the  differences,  as 
well  as  the  points  of  resemblance ;  otherwise  the  analogy 
will  frequently  mislead  us.  In  comparing  a  bird  with  an 
ox,  we  should  not  infer  that  the  two  are  'of  the  same 
class,  because  they  have  a  skull,  a  spinal  column,  and  a 
double  heart,  or  that  the  bird's  wings  are  used  in  moving 
upon  the  ground,  because  they  are  analogous  to  the  ox's 
forelegs. 

The  usual  course  of  indirect  discovery  is,  to  detect  sim- 
ilarities between  two  or  more  things,  and  then  test  the 
extent  of  the  actual  resemblances  by  means  of  reasoning, 
observation,  and  experiment.  If  the  knowledge  of  the 
mere  resemblances  be  not  the  ultimate  object  sought,  we 
form  hypotheses ;  and,  after  rejecting  those  which  either 
involve  absurdities  or  are  incompatible  with  known  facts, 
we  determine  which  is  the  most  probable,  by  means  of 
analogies,  and  then  test  it,  in  the  manner  already  indi- 
cated. Ready  skill  in  discovering  analogies  is  generally 
acquired  by  means  of  an  accurate  and  extensive  knowl- 
edge of  the  particular,  and  kindred,  subjects,  combined 
with  habits  of  close  and  careful  observation,  and  a  vigor- 
ous power  of  conception. 

The  most  probable  hypothesis  is  generally  that  which 
is  most  consistent  with  known  truths,  and  which  ac- 
counts, in  the  fullest  and  simplest  manner,  for  all  the  phe- 
nomena. It  may  possibly  be  false :  yet  the  best  course 
usually  is,  to  test  it,  before  trying  any  other. 

When  there  is  no  probability  to  guide  us,  we  may  still 
observe  and  experiment :  but  our  labors  will  generally 
prove  abortive,  or  end  in  something  different  from  the 
object  of  our  search.  A  person  sometimes  stumbles  on 


ICO  ORIGINAL  INVESTIGATION.        [CHAP.  IX. 

the  right  hypothesis  at  the  outset,  without  ascertaining 
the  most  probable:  but  the  case  is  usually  otherwise; 
and  indirect  discoveries  of  any  consequence  are  very  rare- 
ly made  by  persons  devoid  of  judgement  and  perspica- 
city, while  they  are  never  accidental. 

In  order  to  success,  we  must  generally  analyse  the 
subject  mentally,  and  thus  ascertain  its  various  parts. 
Things  are  mostly  presented  to  our  immediate  observa- 
tion in  so  complex  a  form  that  it  is  impossible  to  discov- 
er the  object  of  our  investigation,  without  considering 
the  various  parts  in  succession  :  for  nobody  can  consider 
several  points  simultaneously,  when  every  one  of  them 
requires  close  attention  from  the  same  faculty. 

This  analysis  is  equally  useful  in  detecting  analogies, 
deducing  remote  inferences,  or  establishing  hypotheses. 
The  greatest  difficulty  generally  lies,  not  in  actually  ac- 
complishing the  results,  but  in  discovering  clearly  how 
they  are  to  be  effected,  and  in  performing  the  initiatory 
preparations  ;  and,  in  order  to  this,  the  mental  analysis  is 
generally  indispensable.  It  enables  us  to  resolve  a  com- 
plex or  difficult  problem  into  a  number  of  easy  steps, 
every  one  of  which  prepares  the  way  for  effecting  that 
which  follows ;  so  that  we  pass  from  one  to  another  with- 
out any  great  difficulty,  verifying  the  different  processes 
as  we  proceed. 

The  analysis  is  generally  effected  by  concentrating  the 
attention  on  a  particular  point,  considering  it,  in  its  vari- 
ous aspects,  till  we  clearly  see  its  bearings,  then  proceed- 
ing to  another  point,  and  so  on.  The  points  to  be  select- 
ed for  consideration  depend  on  the  nature  of  the  subject 
and  the  object  of  the  investigation. 

In  many  cases,  it  is  impossible  to  reach  our  final  object 
from  any  premises  which  are  strictly  true.  We,  there- 
fore, make  an  assumption  which  is  partially  inaccurate, 
then  deduce  the  consequences,  and  afterwards  discover 
the  modifications  to  be  made  in  our  conclusions,  in  order 
to  render  them  quite  accurate.  The  Astronomer  cannot 
determine  the  future  place  of  a  planet  by  starting  with 
the  truth  regarding  the  various  forces  that  affect  it,  as  no 
human  intellect  can  solve  so  difficult  a  problem.  But  he 
first  assumes  that  it  is  influenced  solely  by  the  Sun  ;  and 
he  afterwards  determines  what  is  due  to  the  disturbing 
influence  of  the  other  planets,  for  which  he  then  makes 
proper  allowances. 


SEC.  3.]  EXPERIMENTS.  161 

Much  judgement  is  often  required  in  discovering  the 
best  course  to  be  adopted,  which  is  frequently  done  only 
after  several  other  methods  have  been  tried,  and  failed : 
and,  therefore,  such  failures  are  to  be  expected,  and  must 
not  discourage  the  investigator.  They  have  often  pre- 
ceded important  discoveries. 

Where  we  are  furnished  with  several  independent 
means  of  testing  the  point  under  consideration,  the  best 
course  generally  is,  to  trace  carefully  the  result  to  which 
we  are  led  by  each,  irrespective  of  the  others.  If  all  con- 
duct us  legitimately  to  the  same  result,  the  conclusion  is 
firmly  established.  If  the  results  are  inconsistent,  there 
must  be  some  fallacy  in  our  proceedings,  since  one  sound 
conclusion  cannot  possibly  be  inconsistent  with  another ; 
and  we  should  search  till  we  detect  the  error.  If  some 
of  the  processes  merely  fail  to  give  any  reliable  result, 
while  others  conclusively  establish  the  point,  the  nega- 
tive results  are  entitled  to  no  weight. 

Experiments  frequently  furnish  important  aid  in  this 
class  of  discoveries ;  and  the  following  general  rules  will 
assist  us  in  their  application  : 

1.  Form  a  clear  and  precise  notion  of  the  object  of  the 
experiment,  or  the  purpose  which  it  is  designed  to  ac- 
complish. 

2.  Remove,  as  far  as  practicable,  every  source  of  doubt 
or  uncertainty  regarding  the  result,  so  that  it  may  be  as 
unequivocal  as  possible. 

3.  Test  the  inferences  which  the  result  seems  to  war- 
rant, by  the  principles  of  sound  reasoning,  so  as  to  obvi- 
ate fallacious  conclusions. 

4.  Where  a  result  is  equivocal,  or  otherwise  unsatisfac- 
tory, repeat  the  experiment,  with  such  variations  as  seem 
best  calculated  to  remove  the  difficulty. 

5.  If  the   result  should   still  continue  unsatisfactory, 
adopt,  if  practicable,  a  different  kind  of  experiment, 
which  promises  to  obviate  the  difficulty. 

If  these,  or  similar,  rules  are  not  observed,  the  results 
will  be  more  likely  to  rivet  error  and  conceal  truth,  than 
to  dissipate  the  former  or  establish  the  latter,  since  prej- 
'udice  will  persuade  the  investigator  to  adopt  its  own  dic- 
tates, and  reject  hostile,  though  necessary,  inferences. 

Before  drawing  a  final  conclusion,  we  should  have  sat- 
isfactory proof  that  we  know  everything  requisite  to  a 
right  view  of  the  subject  under  investigation  :  otherwise 


162  ORIGINAL  INVESTIGATION.       [CHAP.  IX. 

we  shall  probably  adopt  some  theory  which  misrepre- 
sents the  subject.  Most  of  the  objectionable  theories 
ever  broached  were  owing,  in  a  great  measure,  to  ignor- 
ance of  some  important  parts  of  the  subject,  which  were 
overlooked. 

§  4.  OF  INVENTION. — Relations  of  Invention  to  indirect  Discovery. — 
Use  of  Analogy. — Inventions  of  two  kinds. — Principal  fields  of  In- 
vention.— Mathematics.  — Physics.  — Education. — Social  Institu- 
tions.— Requisites  in  Inventions  immediately  regarding  Man. — 
Why  Legislative  and  Social  have  not  kept  pace  with  Physical  In- 
ventions.— External  aids  of  Invention. — How  the  place  of  Models 
may  be  supplied. 

Invention  resembles  indirect  discovery  so  much  that 
the  remarks  made  in  the  preceding  section  are  mostly 
applicable  to  it.  The  principal  difference  is,  that  we 
have  here  to  contrive  some  means  of  solving  a  given 
problem,  instead  of  discovering  a  proof  or  refutation  of  a 
given  proposition,  or  deducing  remote  inferences.  Hence 
there  is  rather  less  occasion  for  simple  observation  or 
comparison,  and  we  are  more  dependent  on  an  extensive 
and  familiar  acquaintance  with  the  subject  of  investiga- 
tion, and  the  power  of  readily  forming  conceptions  and 
testing  them  by  reasoning  and  experiments. 

Analogy  is  generally  less  available  than  in  discovery : 
yet  it  is  often  of  great  use,  particularly  in  the  earlier 
stages ;  and  many  important  inventions  originated  in  ob- 
serving the  modes  in  which  certain  ends  are  effected  by 
natural  means,  a  source  of  assistance  which  cannot  easily 
be  exhausted. 

Inventions  are  either  physical  or  mental.  The  former 
consist  chiefly  of  tools  or  machines,  such  as  saws,  planes, 
files,  ships,  clocks,  and  steam-engines.  The  latter  consist 
of  means  for  enabling  us  to  acquire  or  retain  knowledge, 
or  to  perform  some  process  with  correctness  and  dis- 
patch. Such  are,  the  ordinary  rules  of  Arithmetic,  and 
all  those  arts  in  which  the  processes  are  not  obvious  or 
dependent  on  machinery,  and  also  the  modes  of  influenc- 
ing emotions  and  opinions. 

The  principal  fields  of  invention  are,  the  mathematical 
and  physical  sciences,  education,  social  institutions,  and* 
the  arts. 

The  objects  of  mathematical  invention  are,  the  solution 
of  problems,  or  the  application  of  Mathematics  to  extend 
the  boundaries  of  Physics.  In  some  cases,  modes  of  ef- 


SEC.  4.]  INVENTION.  163 

fecting  the  desired  results  are  already  known ;  but  they 
are  too  tedious,  or  not  sufficiently  accurate,  or  too  liable 
to  lead  us  into  error.  In  such  cases,  the  inventor's  la- 
bors are  requisite,  until  he  has  discovered  the  means  of 
effecting  the  desired  results  with  the  greatest  attainable 
quickness  and  accuracy. 

In  the  physical  sciences,  the  fields  of  invention  are 
widest  where  the  application  of  Mathematics  is  most  ex- 
tensive. But  there  is  room  for  improved  methods  of 
making  observations  and  experiments  in  others  also ; 
and  these  are  the  principal  means  by  which  they  can  be 
corrected  and  extended.  A  wide  field  for  physical  in- 
vention is  furnished  by  the  application  of  the  various 
natural  forces  or  powers  to  produce  desired  results,  in- 
cluding those  of  gravity,  expansion  and  contraction  of 
substances  by  differences  of  temperature,  chemical  ac- 
tion, heat,  light,  and  electricity.  The  inventor  will  de- 
rive much  aid  from  studying  the  effects  produced  by 
these  agencies,  under  the  various  circumstances  in  which 
they  operate. 

The  principal  subjects  of  invention,  in  education,  are, 
the  best  means  of  disciplining  and  instructing  youth,  so 
that  all  the  faculties  may  be  properly  developed,  while 
the  pupil,  at  the  same  time,  acquires  the  elements  of  use- 
ful knowledge.  No  system  of  education  is  satisfactory, 
•unless  it  effects  both  of  these  objects,  which  are  so  re- 
lated that  the  same  system  which  best  secures  the  one, 
is  also  the  most  favorable  for  accomplishing  the  other. 

In  social  institutions,  the  principal  subjects  of  inven- 
tion are,  public  and  private  law.  The  aims  of  invention, 
in  relation  to  the  former,  are  the  two  following:  1.  To 
ascertain  that  form  of  government  which  will  be  most 
favorable  to  the  enactment,  enforcement  and  perpetuity 
of  the  best  private  laws.  2.  To  determine  the  best  laws 
for  regulating  the  intercourse  between  different  nations 
and  their  subjects,  so  that  it  may  be  as  safe,  free  and  mu- 
tually advantageous  as  possible. 

In  all  inventions  of  which  man  is  the  immediate  sub- 
ject, the  investigator  should  be  guided  by  a  correct  and 
extensive  knowledge  of  human  nature  in  general :  other- 
wise his  inventions  will  possibly  be  suitable  only  for  im- 
aginary beings.  Another  important  requisite,  in  all  in- 
ventions of  this  kind  which  are  intended  for  immediate 
practice,  is,  a  knowledge  of  the  peculiar  characteristics 


164  ORIGINAL  INVESTIGATION.       [CHAP.  IX. 

and  circumstances  of  the  parties  for  whom  they  are  de- 
signed. A  system  of  education"  or  government,  for  in- 
stance, may  be  the  best  possible  for  one  community,  and 
decidedly  objectionable  for  another,  owing  to  the  wide 
disparity  in  their  characters  and  circumstances. 

Improvements  in  social  institutions  have  not  generally 
kept  pace  with  those  in  physical  science,  because  the 
laws  on  which  they  should  be  based  are  not  so  easily  dis- 
covered, and  the  pursuit  has  generally  been  conducted 
against  the  influence  of  strong  prejudices  and  external 
disadvantages.  Yet  these  difficulties  do  not  render  pro- 
gress impossible. 

In  all  inventions,  we  may  be  aided  by  writings,  draw- 
ings, and  experiments;  and,  in  several,  chiefly  of  the 
physical  kind,  we  derive  much  assistance  from  models,  or 
actual  representations  of  the  proposed  invention.  The 
faculty  of  Conception  is  seldom  so  powerful  that  it  can 
figure  forth  and  clearly  discern,  at  a  single  effort,  all  the 
parts  and  relations  of  a  complex  invention.  Hence  the 
inventor  first  makes  a  representation  of  his  present  con- 
ception ;  and  when  he  has  this  clearly  before  him,  im- 
provements and  additions  are  easily  planned  and  effect- 
ed. A  carefully  constructed  model,  after  being  fairly 
tried,  generally  gives  us  a  good  view  of  the  defects  and 
merits  of  the  invention,  as  it  now  stands,  and  suggests 
improvements  better  than  anything  else,  short  of  a  long 
practical  trial. 

In  many  cases,  experiments  and  the  construction  of 
models  are  impracticable;  yet  simple  observation  may 
answer  the  same  purpose.  Thus,  if  a  certain  scheme  of 
social  organization  has  occurred  in  History,  in  circum- 
stances which  gave  it  a  fair  trial,  and  it  was  found  to 
fail,  no  model  or  experiment  is  requisite. 


SEC.  l.j          SOUKCES   AND   APPLICATIONS,  &C.  165 


CHAPTER  X. 

OF   CAUSES   AND   EFFECTS. 

§  1.  SOURCES  AND  APPLICATIONS  OF  THE  KNOWLEDGE  OP  CAUSES 
AND  EFFECTS. — Two  classes  of  Causes,  and  means  of  ascertaining 
them. — Experience,  when  requisite,  and  when  not. — Advantages 
of  knowing  the  Laws  of  Nature. — Inadequate  Agencies. — Means 
of  determining  a  Cause  indirectly. — Important  application  of  the 
Laws  of  Causation.  —  Advantages  of  a  knowledge  of  Controlla- 
ble Causes — and  of  Causes  beyond  Control. — Importance  of  know- 
ing what  Effects  will  be  produced  by  a  given  Agency. — Tracing  the 
implied  Consequences  of  a  known  Agency. — Moral  bearings  of  a 
Knowledge  of  Causes. — Cause  and  Effect  signs  of  each  other. — 
Important  Distinction,  and  Practical  application. — Caution. 

CAUSES  may  be  divided  into  necessary  and  contin- 
gent. The  former  consist  of  those  whose  existence  is 
discerned  intuitively,  without  any  direct  aid  from  Com- 
prehension :  the  latter  include  those  whose  existence  and 
nature  cannot  be  known  without  the  aid  of  experience, 
although,  as  causes  are  distinguishable  from  mere  phe- 
nomena, they  are  never  discovered  without  the  applica- 
tion of  Intuition. 

Contingent  causes  cannot  generally  be  discovered  with- 
out the  aid  of  observation  or  experiment,  since  there  are 
several  agencies  to  which  the  effects  or  phenomena  may 
be  attributed,  and  experience  alone  can  inform  us  which 
is  the  actual  cause.  Thus,  if  a  rock  roll  down  from  its 
former  fixed  position,  on  a  mountain's  side,  we  know  in- 
tuitively that  there  must  be  some  cause  for  the  change : 
but  what  the  particular  cause  is,  must  be  learned  from 
the  circumstances  of  the  case. 

On  the  other  hand,  the  existence  and  general  nature 
of  necessary  causes  are  known  solely  by  Intuition.  Thus, 
we  know  that  the  voluntary  acts  of  a  man  are  caused  by 
motives,  which  must  be  objects  that  he  deems  desirable. 
So  we  know,  independently  of  experience,  that  the  causes 
of  our  ordinary  apprehensions  are,  external  substances, 
distinct  from  ourselves,  and  that  an  exquisitely  finished 
time-keeper  is  the  production  of  skill,  and  neither  of 
chance  nor  of  a  bungling  artisan.  Wherever  the  phe- 


1GG  CAUSES  AND  EFFECTS.  [CHAP.  X. 

r/omenon  is  such  that  Reason  can  demonstrate  it  could 
proceed  only  from  a  particular  kind  of  agency,  we  do  not 
require  the  aid  of  experience  to  teach  us  that  it  is  the 
effect  of  such  an  agency. ' 

Although  experience  generally  lies  at  the  root  of  our 
knowledge  of  the  particular  cause  of  an  occurrence,  yet 
we  need  not  have  recourse  to  it,  in  every  case,  in  order 
to  ascertain  the  very  agency  concerned.  For,  when  once 
we  have  found  out  that  all  the  changes  which  usually 
take  place  in  nature,  are  immediately  owing  to  certain 
agencies,  and  that  these  act  with  great  uniformity,  we 
can  frequently  determine  the  cause  of  a  phenomenon, 
without  any  elaborate  investigation.  Thus,  in  the  case 
mentioned  above,  if  we  know  the  effects  of  freezing  wa- 
ter, and  that  the  fall  of  the  rock  was  preceded  by  a  se- 
vere frost,  we  have  at  once  an  explanation  of  the  occur- 
rence ;  and  when  we  see  a  rainbow,  we  know  its  cause, 
without  any  investigation. 

A  knowledge  of  the  laws  of  nature  frequently  enables 
us,  not  only  to  ascertain  readily  the  cause  of  a  phenome- 
non, but  also  to  exclude  possible  causes,  as  being  inade- 
quate, when  the  particular  cause  is  still  undetermined. 
An  agency  is  inadequate  when  the  laws  of  its  operation, 
or  its  want  of  skill  or  power,  are  incompatible  with  the 
supposition  of  its  being  the  cause  of  the  phenomenon  in 
question.  Thus  we  cannot  attribute  warm  weather  to 
the  position  of  the  Moon,  because  it  neither  gives  out 
nor  produces  any  heat  itself,  nor  does  it  influence  that 
imparted  by  the  Sun,  in  any  measurable  degree. 

A  knowledge  of  the  requisites  necessary  to  produce  a 
certain  result,  enables  us  to  determine  the  nature  of  a 
cause  of  which  we  have  no  direct  knowledge.  Thus,  we 
judge  of  the  skill  of  a  mechanic  solely  from  a  view  of  his 
handiwork ;  and  we  ascertain  the  force  of  volcanic  ac- 
tion by  witnessing  the  effects  which  it  has  produced. 
Thus,  also,  we  ascertain  the  motives  and  characters  of 
men,  when  there  are  no  reliable  means  of  doing  so  di- 
rectly, from  continued  observation  of  their  conduct.  The 
nature  of  the  inapprehensible  cause  is  learned  from  its 
effects,  as  the  quality  of  an  unseen  tree  is  known  by  its 
fruits. 

A  knowledge  of  the  cause  of  a  phenomenon  enables  us 
to  modify  it  at  pleasure,  wherever  we  can  control  the 
former.  Thus,  if  a  certain  disease  is  found  to  be  caused 


SEC.  1.]         APPLICATIONS  OF  KNOWLEDGE.  167 

by  miasms,  arising  from  a  marsh  which  can  be  drained, 
we  can  stop  its  ravages  whenever  we  like ;  and  if  a  pub- 
lic speaker  knows  what  causes  will  produce  certain  emo- 
tions in  his  hearers'  minds,  and  can  apply  them,  he  may 
produce  these  emotions  at  pleasure. 

Where  the  cause  is  not  directly  under  *our  control,  a 
knowledge  of  its  nature  may  still  enable  us  to  counteract 
its  influence.  Thus,  we  may  neutralize  the  effects  of 
miasms  which  we  cannot  remove,  by  avoiding  those  ex- 
posures and  excesses  which  render  us  peculiarly  suscepti- 
ble of  their  influence;  or  we  may  directly  counteract 
them,  by  artificial  heat  or  warm  clothing. 

When  the  object  is,  not  to  avoid,  but  to  secure,  effects 
whose  causes  are  not  under  our  control,  a  knowledge  of 
these  causes  aids  us  in  finding  that  of  which  we  are  in 
search.  Thus,  a  knowledge  of  the  origin  of  coal  directs 
us  to  look  for  valuable  mines  only  in  such  rocks  as  were 
deposited  while  vegetation  was  very  luxuriant;  and  it 
informs  us  that  no  coal  whatever  is  to  be  found  in  the 
non-fossiliferous  rocks,  and  that  no  extensive  deposits  can 
be  expected  either  in  the  oldest  fossiliferous  rocks  or  in 
those  of  recent  formation. 

When  the  cause  is  beyond  even  our  indirect  control,  a 
knowledge  of  its  existence  and  nature  may  still  enable  us 
to  keep  beyond  the  reach  of  its  influence,  and  thus  avoid 
the  pernicious  effects.  If  a  person  has  contracted  a  dis- 
ease, by  living  in  a  very  damp  locality,  he  may  possibly  re- 
move to  a  dry  atmosphere,  and  thus  get  well,  whereas, 
if  he  knew  not  the  cause  of  his  ailment,  or  attributed  it 
to  some  imaginary  agency,  he  would  be  more  likely  to 
be  injured  than,  benefited  by  attempts  to  effect  a  cure. 

It  is  equally  important  to  know  what  effects  will  be 
produced  by  a  given  agency,  acting  in  peculiar  circum- 
stances. A  knowledge  of  the  properties  of  steam  and 
electricity  enables  us  to  produce  results  that  would  once 
have  appeared  incredible ;  and,  by  knowing  the  effects 
of  certain  mental  agencies,  we  can  influence  the  views, 
feelings,  and  conduct  of  others,  and  remove  what  is  bad, 
or  improve  what  is  weak  or  defective,  in  our  own  char- 
acters. 

A  knowledge  of  the  nature  of  a  certain  agency  often 
enables  us  to  ascertain  the  existence  of  effects,  of  which 
we  have  no  other  evidence  except  that  they  must  result 
from  the  agency.  Thus,  many  facts  in  Astronomy  Avere 


168  CAUSES  AND  EFFECTS.  [CHAP.  X. 

discovered,  as  necessary  effects  of  the  force  of  gravity, 
before  they  were  known  by  observation. 

By  deducing  the  implied  consequences  of  a  known 
agency,  we  can  often  discover  other  truths,  beyond  its 
mere  effects.  Thus,  the  effect  of  the  valves  in  the  blood- 
vessels is  simply  to  check  a  retrogressive  or  backward 
course  of  the  blood,  as  it  circulates  in  the  arteries  and 
veins;  and  this  is,  no  doubt,  the  object  for  which  they 
were  formed :  but,  by  investigating  this  object,  Harvey 
discovered  the  circulation  of  the  blood ;  and  other  im- 
portant physiological  discoveries  have  been  made  in  the 
same  way. 

A  knowledge  of  causes  is  as  important  in  its  moral 
bearings  as  in  any  other.  When  we  view  an  admirable 
piece  of  mechanism,  and  understand  the  skill  and  dexte'r- 
ity  necessary  to  plan  and  execute  it,  we  partake,  through 
sympathy,  in  a  greater  or  less  degree,  of  the  emotions  of 
him  who  produced  it :  for  these  feelings  are  evidently  de- 
pendent on  a  knowledge  of  the  causes  that  produced  the 
results,  and  proportional  to  its  extent  and  accuracy.  It 
is  for  this  reason  that  a  good  artisan  beholds  a  master- 
piece with  much  greater  pleasure  than  one  who  supposes 
that  such  things  can  be  produced  as  easily  as  common 
tools. 

The  most  important  aspect  of  this  subject  is,  that  which 
regards  the  works  of  the  Eternal  Architect.*  These  are 
incessantly  presented  to  our  view,  in  vast  profusion,  and 
under  an  immense  diversity  of  forms,  from  the  depths  of 
the  Earth  (whence  have  so  often  issued  streams  of  liquid 
fire,  bearing  the  elements  of  future  fertility,  mixed  with 
iron,  gems,  and  gold)  to  those  remotp  constellations 
whose  numbers,  sizes  and  distances  are  so  great  that  the 
contemplation  of  the  whole  amazes  and  confounds  the 
mind. 

Not  only  does  a  knowledge  of  the  agencies  that  oper- 
ate in  nature,  enable  us  to  supply  many  defects  in  our 
knowledge  of  its  phenomena,  and  to  form  a  more  correct 
and  extensive  notion  of  the  creation  than  is  otherwise 
possible,  but,  when  we  understand  the  difficulties  which 
have  been  overcome,  in  accomplishing  the  results  that  we 
behold,  and  learn  the  origin  and  purpose's  of  the  various 
parts,  we  obtain  an  effective  knowledge  of  the  Most  High, 
and  partake  of  those  emotions  which  unite  us  to  our  Cre- 
ator, and  which  alone  can  satisfy  man's  immortal  mind, 
when  all  lower  enjoyments  shall  have  ceased. 


SEC.  2.]         APPLICATIONS  OF  KNOWLEDGE.  169 

As  cause  and  effect,  or  the  common  effects  of  a  cause, 
are  inseparably  connected,  wherever  there  is  no  interfer- 
ing or  counteracting  agency,  they  are  signs  of  each  oth- 
er ;  and,  therefore,  when  one  is  known  to  operate  or  ex- 
ist, the  other  may  be  inferred.  It  is  thus  that  the  geolo- 
gist discovers  the  causes  of  phenomena  long  after  they 
have  ceased  to  operate.  So,  a  physician  learns  the  ori- 
gin, character,  and  future  course,  of  a  disease,  from  pres- 
ent symptoms ;  and  a  statesman  sometimes  foresees  fu- 
ture events,  as  the  effects  of  existing  agencies.  In  this 
way  we  learn  many  past  and  future  contingencies,  since 
they  are  connected  with  the  present  as  cause  and  effect, 
or  successive  effects  of  a  common  cause ;  and  we  may  fre- 
quently learn  the  present  unseen  from  the  seen,  since  the 
one  either  produces  the  other,  or  both  are  contempora- 
neous results  of  the  same  agency. 

We  must  distinguish  a  knowledge  of  the  effects  of  cer- 
tain agencies,  or  of  the  causes  of  particular  phenomena, 
from  that  of  the  mode  in  which  the  causes  operate.  We 
may  possess  the  former,  while  we  arc  quite  ignorant  of 
the  latter.  Thus,  we  may  know  that  certain  poisons 
speedily  destroy  life,  without  knowing  how  they  do  so, 
just  as  we  know  that  we  move  our  limbs  at  pleasure,  al- 
though the  mode  in  which  we  do  so,  is  a  profound  mys- 
tery. 

The  value  of  the  former  kind  of  knowledge  is  evident- 
ly independent  of  the  latter,  and  it  maybe  of  the  utmost 
importance,  though  we  should  continue  quite  ignorant 
of  the  mode  of  operation.  This,  however,  is  a  legitimate 
subject  of  inquiry,  though  we  shall  often  find  that  we  can 
make  little  real  progress  in  the  investigation.  Words 
have  sometimes  been  freely  employed,  in  such  cases, 
while  those  who  used  them  had  no  clear  idea  of  what 
they  meant  by  them. 

§  2.  VARIOUS  KINDS  or  CAUSES. — Efficient  and  Conditional  Causes. 
—  Immediate,  Mediate,  and  Ultimate  Causes. —  Only  Ultimate 
Causes. — Common  Error. — Remarks  on  the  Laws  of  Nature,  and 
on  Ultimate  Causes. 

All  causes  are  either  efficient  or  conditional.  The  for- 
mer consist  of  those  forces  which  actually  produce  the 
effects,  and  are  otherwise  termed  poioers :  the  latter  are, 
the  circumstances  or  conditions  which  are  requisite  to 
the  production  of  the  effects ;  and  thev  are  also  termed 

H 


170  CAUSES  AND  EFFECTS.  [CHAP.  X. 

occasioning  causes,  or  simply  conditions.  In  popular 
language,  that  is  generally  termed  the  cause  which  is 
most  subject  to  change,  whether  efficient  or  conditional. 
Thus,  if  a  man  slips,  when  walking  on  ice,  his  fall  is  said 
to  be  caused  By  its  slipperiness,  although  this  is  only  a 
conditional  cause,  while  the  force  of  gravity  is  the  effi- 
cient cause. 

Causes,  again,  are  immediate,  mediate,  or  ultimate. 
The  immediate  cause  is  that  which  directly  produces  the 
result,  without  the  intervention  of  any  second  agency. 
The  ultimate  cause  is,  the  good  or  evil  which  originates 
the  volition  that  leads  to  an  effect.  A  mediate  cause  is 
one  that  intervenes  between  the  ultimate  and  the  imme- 
diate cause,  and  forms  a  necessary  link  in  the  chain. 
When  a  blacksmith  hammers  a  bar  of  iron,  the  stroke 
of  the  hammer  is  the  immediate  cause;  the  thing  which 
led  him  to  will  the  hammering  is  the  ultimate  cause ;  and 
the  movements  of  his  arm  are  an  intermediate  cause. 

The  causes  of  volitions  are  the  only  ultimate  causes, 
since  eternal  spontaneous  motions  of  inanimate  beings 
would  be  effects  without  any  adequate  causes ;  and,  if 
such  beings  are  at  rest,  they  will  evidently  move  only  as 
they  are  moved.  Hence,  although  they  often  communi- 
cate, they  never  originate  motion,  either  in  themselves  or 
in  other  beings. 

When  a  phenomenon  has  been  shown  to  belong  to  a 
known  class,  it  is  often  thought  that  its  ultimate"  cause 
has  been  unfolded,  Avhile,  in  fact,  no  explanation  has  been 
given  of  any  such  cause.  Thus,  when  certain  motions 
of  the  Moon  are  traced  to  the  force  of  gravity,  many 
think  that  their  ultimate  cause  has  been  explained,  where- 
as the  law  of  gravitation  explains  neither  the  nature  nor 
the  origin  of  the  force  which  produces  those  motions. (15) 

Most  of  the  laws  of  nature  arc  merely  inductions  re- 
garding occurrences  or  phenomena,  and  give  no  expla- 
nation of  any  cause  whatever.  When  we  say,  for  in- 
stance, that  "metals  expand,  on  the  application  of  heat," 
we  do  not  explain  why  any  of  them  does  so.  Even  those 
laws  of  nature  which  express  caiises,  seldom  explain  the 
ultimate  cause.  Thus,  it  is  a  law  of  nature  that  "  heat 
expands  gases ;"  but  this  does  not  explain  why  it  does 
so  ;  for  heat  is  as  destitute  of  thought  as  the  gases.  • 

In  several  branches  of  Physics,  it  is  not  necessary  to 
investigate  ultimate  causes ;  but,  even  there,  it  is  a  seri- 


SEC.  3.]  METHODS  OF  DISCOVERING.  171 

ous  error  to  suppose  that  we  know  more  of  the  matter 
than  we  actually  do ;  and,  in  many  physical  researches, 
the  consideration  of  ultimate  causes  is  of  much  use  in 
promoting  discovery.  In  the  mental  sciences,  the  sub- 
ject is  one  of  the  utmost  importance. 

§  3.  METHODS  OF  DETERMINING  CAUSES  AND  EFFECTS.— Divisions  of 
the  subject. — Inadequate  and  absent  Agencies. — Effect  attributa- 
ble to  only  one  Cause. — Case  of  combined  Agencies. — Means  of 
determining  the  influence  of  each. — Application  of  the  fact  that  Ef- 
fects follow  their  Causes. — Proper  course  when  Cause  and  Effect 
appear  simultaneously. — Application  of  a  knowledge  of  the  Laws 
of  Nature. — Frequent  means  of  ascertaining  the  existence  or  ab- 
sence of  possible  Agencies,  and  the  effect  or  intensity  of  a  known 
Agency. — Caution. — Proper  course  regarding  known  and  un- 
known* Agencies. — Seven  Principles  applicable  where  preceding 
methods  fail,  with  Remarks. — Proper  course  where  one  Principle 
gives  equivocal  Results. — Sole  and  combined  Agencies. — Means 
of  ascertaining  the  nature  and  extent  of  a  particular  Agent's  influ- 
ence.— Use  of  Analogy. — Common  Mistake. — Use  of  Experiments. 
— Effects  which  cannot  be  traced  to  any  known  Cause. — Errors 
regarding  them. — Mode  of  tracing  a  chain  of  Causes. — Means  of  de- 
termining what  Causes  would  produce  a  supposed  Effect. — Modes 
of  ascertaining  the  effects  of  a  known  Cause. — Use  of  Experiments 
in  such  cases. — Proper  course  where  these  are  inapplicable. — 
Means  of  tracing  the  Effects  of  Causes  which  have  ceased  to  oper- 
ate.— Independent  Effects.— Cases  of  Reciprocal  Action. — General 
Requisites,  and  Cautions. 

All  inquiries  regarding  causes  and  effects  are  neces- 
sarily either  into  the  causes  of  known  or  supposed  effects, 
or  into  the  effects  of  known  or  supposed  causes ;  and 
each  inquiry  contains  three  subdivisions,  which  may  be 
stated  as  follows : 

A.  1.  What  causes,  now  inoperative,  have  produced 
known  effects.     2.  What  causes,  now  operating,  produce 
known  effects.     3.  What  causes  would  produce  certain 
supposed  effects. 

B.  1.  What  effects  have  been  produced  by  known 
causes,  no  longer  operative.     2.  What  effects  known  op- 
erating causes  are  now  producing.    3.  What  effects  would 
certain  supposed  causes  produce. 

Both  classes  of  inquiries  are  based  on  the  same  general 
principles,  so  that  we  need  not  discuss  every  subdivision 
separately.  In  many  cases,  also,  we  do  not  know  before- 
hand  whether  the  causes  are  still  operative  or  not,  as 
that  can  be  learned  only  when  we  have  ascertained  what 
they  really  are. 


172  CAUSES  AND  EFFECTS.  [CHAP.  X. 

The  two  intuitions  that  a  cause  must  be  adequate  to 
produce  the  effect,  and  that  it  cannot  act  where  it  is  not, 
except  by  a  medium,  frequently  enable  us  to  exclude 
many  possible  agencies  from  the  list  of  admissible  causes. 
Thus,  the  vapors  arising  from  cooking  utensils  cannot  be 
the  cause  of  heavy  rains ;  and  a  man  who  was  in  China 
when  a  murder  was  committed  in  New  York  cannot 
have  had  any  direct  hand  in  it.  In  applying  those  in- 
tuitions, however,  we  should  ascertain  that  the  agency 
in  question  is  inadequate  or  absent :  for  this  has  frequent- 
ly been  assumed  where  the  case  was  otherwise. 

In  many  instances,  the  circumstances  are  such  that  an 
effect  can  be  attributed  only  to  one  cause.  These  are 
chiefly  where  we  know  that  no  other  adequate  agency 
operates  in  producing  the  result.  Thus,  the  immediate 
cause  of  the  change  of  seasons  must  be  solely  the  differ- 
ent directions  of  the  Sun's  rays,  since  there  is  no  other 
agency  which  has  even  a  tendency  to  produce  thoso 
changes.  But  we  should  know  that  no  such  agency  ex- 
ists: for  we  are  liable  to  assume  this,  when  we  are  sim- 
ply ignorant  of  the  existence  of  any  such  cause,  while  we 
may  erroneously  assume  something  else  as  the  cause, 
which  is  a  mere  antecedent  or  concomitant.  The  requi- 
site knowledge  is  generally  obtained  by  extending  our 
observations,  or  repeating  our  experiments,  until  the  sup- 
position of  casual  or  latent  agencies  is  excluded. 

A  certain  agency  frequently  operates  in  producing  a 
result,  while  it  is  only  one  of  several  causes,  each  of  which 
may  be  inadequate  to  produce  the  effect :  and,  therefore, 
before  we  can  legitimately  conclude  that  an  effect  is  pro- 
duced solely  by  a  single  agency,  we  must  know  that  no 
other  contributes,  in  any  degree,  to  produce  the  result. 

Where  several  agencies  co-operate,  it  is  often  import- 
ant to  ascertain  their  comparative  influence.  This  is  to 
be  done,  either  by  reasoning  from  intuitive  principles,  or 
by  observing  the  force  of  each,  where  it  acts  singly.  All 
we  can  ascertain,  in  many  cases,  is,  that  one  agency  is 
much  more  potent  than  another ;  but  this  usually  answers 
the  purpose,  and  greater  accuracy  is  of  little  consequence. 

Where  the  agents  are  different  in  their  nature,  and 
every  one  is  essential  to  the  production  of  the  effect,  we 
cannot  even  institute  a  comparison  between  their  respect- 
ive influences.  Thus,  we  cannot  rightly  say  that  food  is 
more  essential  than  water  to  sustain  life,  since  each  is 


SEC.  3.]  METHODS  OF  DISCOVERING.  173 

indispensable.  But  where  the  agents  are  alike  in  kind, 
and  their  power  admits  of  measurement,  while  the  effects 
of  one  are  only  cumulative  to  those  of  another,  we  may 
possibly  ascertain  the  exact  amount  due  to  each.  Thus, 
when  several  steam-engines  are  employed  to  drain  a  pool, 
it  may  be  easy  to  ascertain  the  exact  amount  of  water 
removed  by  each. 

Where  several  similar  causes  unite  in  producing  a  cer- 
tain result,  the  total  effect  is  generally  a  combination  of ' 
the  separate  results.  If  two  mechanical  forces  act  in  the 
same  direction,  the  combined  force  is  equal  to  their  sum  ; 
and,  if  they  act  directly  against  each  other,  the  result  is 
equal  to  their  difference.  But  experience  is  often  neces- 
sary, in  order  to  determine  the  actual  results :  for  there 
are  various  exceptions  to  the  general  rule.  White  light, 
for  example,  is  a  combination  of  blue,  yellow,  and  red, 
each  of  which  is  much  darker  than  the  compound. 

Every  effect  is  necessarily  preceded  by  its  immediate 
or  mediate  cause ;  and  this  often  enables  us  to  determ- 
ine whether  a  particular  agency  is  concerned  in  produc- 
ing a  certain  result.  For,  if  the  agency  appears  subse- 
quently, or  even  simultaneously,  it  cannot  be  the  cause. 
But  when  an  agent  acts  continuously,  and  the  effect  ap- 
pears in  the  same  manner,  cause  and  effect  appear  simul- 
taneously, although  every  .part  of  the  effect  succeeds  the 
particular  act  by  which  it  is  produced.  Here  we  must 
compare  the  time  when  the  cause  began  to  operate  with 
that  when  the  effect  first  appeared,  and  the  time  when 
the  former  ceases  to  act,  with  that  when  the  latter  ceases 
to  appear. 

The  peculiar  nature  of  many  agents  excludes  them 
from  the  supposition  of  their  being  concerned  in  produc- 
ing certain  results.  For  experience,  and  the  intuitions 
of  causation,  inform  us  that  they  either  are  neutral,  or 
that  their  results  differ  materially  from  the  object  in 
question,  or  that  they  are  even  the  reverse.  We  cannot 
consider  the  geological  formation  of  a  country  the  cause 
of  the  change  of  seasons,  or  unstratified  rocks  as  the  re- 
sults of  aqueous  deposits,  or  light  the  cause  of  darkness. 

This  method  of  limiting  the  possible  causes  of  an  ef- 
fect supposes  that  we  already  know  the  characteristics 
of  the  various  agencies ;  and  hence  it  becomes  more  ap- 
plicable as  knowledge  advances.  Owing  to  their  gen- 
eral ignorance,  rude  nations  have  often  assigned  agen- 


174  CAUSES  AND  EFFECTS.  [CHAP.  X. 

cies  as  causes  of  results  with  which  an  intelligent  person 
would  readily  know  that  they  have  no  connection.  Pieces 
of  human  mummy,  ground  to  a  powder,  were  long  con- 
sidered excellent  medicines  for  certain  disorders,  al- 
though everything  of  that  kind  is  as  useless  for  any  such 
purpose  as  it  is  disgusting. 

An  extensive  knowledge  of  the  laws  of  nature  enables 
us,  not  only  to  exclude  certain  agencies  from  the  list  of 
admissible  causes,  but  also  to  conjecture  the  actual  cause, 
amid  many  which  are  not  absolutely  inadmissible.  Thus, 
by  knowing  the  properties  of  water  and  heat,  we  can 
readily  ascertain  the  causes  of  many  geological  phenom- 
ena. A  knowledge  of  those  laws  also  aids  us  in  determ- 
ining when  an  unexplained  phenomenon  is  to  be  attrib- 
uted to  some  agency  previously  unknown,  and  in  form- 
ing an  accurate  conception  of  the  nature  of  that  agency. 

The  existence  or  absence  of  a  possible  agency  may  fre- 
quently be  ascertained  by  observing  whether  or  not  its 
constant  effect  is  present,  on  the  principle,  formerly  stated, 
that  the  presence  of  an  eifect  proves  the  existence  of  its 
cause,  and  the  absence  of  an  effect  proves  the  absence 
of  its  cause.  Thus,  the  formation  of  ice  on  the  waters 
proves  that  the  weather  has  been  cold,  and  its  absence 
proves  the  reverse.  In  applying  this  principle,  we  must 
beware  of  assuming,  without  proof,  that  an  effect  can 
have  proceeded  only  from  a  particular  cause,  or  that  the 
phenomenon  in  question  is  a  constant  effect.  We  should 
also  ascertain  that  there  has  been  no  extraneous  inter- 
ference with  the  agencies  or  phenomena,  either  accident- 
ally or  from  design. 

In  determining  the  effect  or  intensity  of  an  agency, 
we  are  guided  by  the  intuitions  that  like  effects  will  fol- 
low, in  the  same  circumstances,  and  that  an  effect  which 
depends  solely  on  a  particular  cause,  varies  in  proportion 
to  the  changes  in  the  cause  /  and  changes  in  the  effect 
must  have  been  preceded  by  corresponding  changes  in  the 
cause.  Thus,  a  knowledge  of  one  element  enables  us  to 
know  the  amount  of  the  other.  But  we  must  know  that 
no  other  agency  is  concerned  :  otherwise  our  conclusions 
may  be  very  erroneous.  Heat  generally  expands  liquids ; 
but  it  contracts  water,  when  near  the  freezing  point; 
and  when  it  reaches  the  boiling  point,  instead  of  farther 
expanding,  it  evaporates  in  the  form  of  steam. 

In  searching  for  the  cause  of  a  phenomenon,  we  should 


SEC.  3.]  GENERAL  PRINCIPLES.  1*75 

first  ascertain  whether  it  is  not  produced  by  some  known 
or  familiar  agency :  for,  until  this  is  done,  we  can  evi- 
dently have  no  proof  that  it  results  from  an  unknown  or 
new  agent.  We  should  make  no  assumptions  in  favor 
of  either  class  of  agencies,  but  be  guided  by  probabilities 
and  proofs.  The  mere  fact  that  a  certain  agency  oper- 
ates, does  not  prove  that  it  is  the  cause  of  a  particular 
phenomenon,  with  which  there  is  no  proof  that  it  is  con- 
nected, and  which  may  be  wholly  produced  by  some  oth- 
er agency. 

Where  none  of  the  preceding  methods  furnishes  the 
requisite  information,  we  must  have  recourse  to  farther 
observations  or  experiments:  but  sometimes  the  former 
are  sufficient,  and  the  latter  are  impracticable :  in  other 
cases,  these  aiford  the  readiest  means  of  solving  the  prob- 
lem. In  all  cases  of  this  kind,  important  aid  may  be  de- 
rived from  the  following  principles,  which  are  only  mod- 
ifications of  those  of  causation,  already  stated. 

1.  The  effect  must  always  appear  where  the  agency  op- 
erates freely,  and  never  appear  where  it  has  not  previous- 
ly acted.     Hence,  if  the  supposed  cause  is  found  to  act 
freely,  without  being  followed  by  the  effect  in  question, 
or  if  this  is  found  to  exist,  where  the  agency  has  not  op- 
erated, it  cannot  be  the  cause. 

2.  The  commencement  of  the  free  action  of  the  agency 
must  be  followed  by  the  appearance  of  the  effect,  where  all 
other  things  continue  the  same  as  formerly  /  and  the  ef- 
fect must  cease  to  be  directly  produced,  when  the  agency 
ceases  to  operate.    Hence,  where  the  supposed  cause  com- 
mences to  act  freely,  and  the  effect  in  question  does  not 
begin  to  appear,  or  where  this  does  not  cease  to  be  di- 
rectly produced,  when  the  supposed  cause  has  ceased  to 
operate,  the  agency  is  not  the  cause.    The  continued  mo- 
tion of  a  body,  after  it  has  once  been  moved,  seems  to 
contradict  this  principle :  but,  in  reality,  it  does  not ;  for 
the  motion  is  only  a  continuation  of  the  body's  preced- 
ing state,  without  any  additional  effect.    When  a  moving 
body  changes  either  its  direction  or  its  velocity,  there  is 
a  change,  for  which  there  must  be  some  adequate  cause : 
but  a  continued  motion,  in  one  direction  and  with  a  uni- 
form velocity,  is  all  the  unchanging  effect  of  the  agency 
which  first  communicated  the  motion. 

3.  Changes  in  the  agency  must  be  followed  by  corre- 
sponding changes  in  the  effect;  and  changes  in  the  effect 


17G  CAUSES  AND  EFFECTS.  [CHAP.  X. 

must  have  been  preceded  by  corresponding  changes  in  the 
agency.  Hence,  if  one  change  without  any  correspond- 
ing change  in  the  other,  the  agency  is  not  the  cause.  It 
must  be  observed,  however,  that,  in  both  cases,  the  cor- 
responding changes  are  not  necessarily  similar :  and,  in 
fact,  although  they  frequently  are  so,  the  case  is  often 
otherwise.  Thus,  a  certain  degree  of  heat  produces  a 
pleasant  sensation,  while  a  great  degree  produces  pain. 

4.  TJie  presence  of  the  peculiar  effects  of  a  certain  agen- 
cy proves  its  previous  action  •  and  the  absence  of  its  uni- 
form results  proves  the  reverse.     Hence,  where  the  for- 
mer are  found,  the  action  of  the  supposed  cause  is  estab- 
lished, and  where  the  latter  are  wanting,  it  is  disproved. 

5.  The  time  that  elapses  between  the  action  of  the  agent 
and  the  appearance  of  the  effect,  must  conform  to  the  na- 
ture of  the  agent  and  the  thing  on  which  it  operates. 
Hence,  if  the  intervening  time  be  greater  or  less,  the  sup- 
posed agency  is  not  the  cause.     Thus,  fire  directly  ap- 
plied to  gunpowder  must  cause  an  explosion  immediate- 
ly or  not  at  all ;  and  a  man  cannot  have  died  from  the 
effects  of  a  little  arsenious  acid  swallowed  seven  years 
previously,  while  the  decease  of  one  who  dies  instantly 
after  taking  a  few  grains  of  that  substance,  must  be  ow- 
ing to  some  other  cause. 

6.  Voluntary  acts  must  proceed  from  motives  known  to 
the  agent,  and  must  harmonize  with  his  character.     A 
motive  wholly  unknown  to  an  agent,  or  one  to  which  he 
attaches  no  weight,  cannot  influence  his  conduct.    Thus, 
brutes  are  never  influenced  by  a  regard  for  a  future  state, 
and  a  thoroughly  selfish  man  never  makes  great  sacri- 
fices purely  from  philanthropic  motives. 

7.  The  motive  must  be  adequate,  .with  reference  to  the 
agentfs  views  and  belief.     A  motive  may  strongly  sway 
one  person  which  would  have  little  influence  with  anoth- 
er.    Hence,  we  must  ascertain,  not  only  that  the  agent 
knew  of  the  supposed  motive,  and  that  it  harmonizes 
Avith  his  character,  but  that  it  is  one  which  may  have 
produced  the  effect  in  question,  under  the  circumstances. 
A  miser  readily  makes  great  sacrifices  for  money :  but 
he  will  not  knowingly  barter  everlasting  bliss  for  it,  as 
this  is  an  impossibility ;  and  hence  the  absurdity  of  the 
stories  that  certain  persons  deliberately  made  a  compact 
with  the  devil,  to  be  his  forever,  on  condition  of  his  im- 
parting to  them  certain  magic  powers.    Nor  can  a  miser 


SEC.  3.]  GENERAL  PRINCIPLES.  177 

be  supposed  to  have  been  influenced  by  the  desire  of 
gain,  when  he  must  have  seen  that  the  consequent  pecu- 
niary loss  would  inevitably  be  much  greater. 

The  preceding  principles  all  assume  that  the  agencies 
operate  freely,  or  without  any  counteraction,  and  that  no 
conflicting  or  extraneous  agencies  interfere  with  the  or- 
dinary results :  and  they  are  applicable  only  upon  these 
conditions. 

There  is  an  evident  necessity  for  an  agent's  conform- 
ing to  one  or  other  of  the  preceding  tests,  in  order  to 
proving  that  it  is  a  cause,  and  not  merely  an  antecedent 
or  concomitant,  supposing  that  there  is  no  other  satis- 
factory proof.  Its  unequivocally  fulfilling  one  of  those 
conditions,  may  furnish  the  requisite  proof.  But  the  ev- 
idence of  one  is  frequently  unsatisfactory,  owing  to  the 
narrowness  of  the  phenomena,  or  the  interference  of  ex- 
traneous or  counteracting  agencies,  or  our  investigations 
having  been  either  too  limited  or  not  conducted  properly. 
Here  we  should  apply  other  tests,  and  continue  our  re- 
searches, till  we  find  some  conclusive  proof.  We  should 
first  try  the  most  probable  cause,  and,  if  the  result  be  ad- 
verse, try  the  next  most  probable,  and  so  on,  till  we  ei- 
ther discover  the  true  cause,  or  find  that  it  lies  wholly 
beyond  our  former  conceptions.  The  principle  that  sim- 
ilar effects  generally  spring  from  similar  causes  will  fre- 
quently suggest  the  nature  of  the  unknown  agency ;  and 
further  aid  may  be  derived  from  the  proper  application 
of  hypotheses. 

In  order  to  establish  an  agent  as  the  sole  cause,  it  must 
appear  that  the  result  is  unaffected  by  changes  in  the 
other  agents  that  might  possibly  be  concerned  in  its  pro- 
duction. When  it  is  found  that  several  agents  are  joint- 
ly concerned,  we  should  test  the  interference  of  others, 
as  if  the  combined  group  were  a  single  agent.  We  find 
what  agents  are  joint  causes  of  a  result,  by  testing  each 
of  them  separately,  until  we  have  ascertained  all  that  are 
so  concerned. 

In  investigating  the  causes  of  the  ordinary  decompo- 
sition of  organic  substances,  for  example,  we  first  find  that 
a  certain  amount  of  heat  is  requisite,  as  one  cause :  for 
wherever  water  freezes,  decomposition  ceases.  Again, 
we  find  that  moisture  is  requisite:  for  decomposition 
never  proceeds  without  the  presence  of  water,  either  in 
the  liquid  or  in  the  gaseous  form.  Lastly,  we  find  that 

H2 


178  CAUSES  AND  EFFECTS.  [CHAP.  X. 

air  is  another  requisite :  for  wherever  it  is  removed,  as 
in  the  exhausted  receiver  of  an  air-pump,  decomposition 
does  not  take  place. 

Thus  we  find  that  ordinary  decomposition  requires  the 
presence  of  heat,  moisture,  and  air ;  and,  as  it  always  pro- 
ceeds where  these  are  present  in  sufficient  quantities,  and 
without  any  counteracting  agency,  these  are  the  only 
causes,  although  other  agents  may  accelerate  or  retard 
their  influence.  The  nature  of  the  process  is  shown  by 
comparing  its  products  with  the  substances  previously  in 
contact.  We  thus  learn  that  some  of  the  organic  com- 
pounds are  decomposed,  and  unite  with  the  gases  that 
compose  air  and  water. 

The  nature  and  extent  of  a  particular  agent's  influence, 
where  it  co-operates  with  others,  is  ascertained  by  com- 
paring the  result  produced  where  it  acts  with  what  ap- 
pears where  it  is  absent  or  inoperative.  Thus,  the  influ- 
ence of  atmospheric  resistance  on  falling  bodies  or  pro- 
jectiles, may  be  determined  by  comparing  the  ordinary 
phenomena  with  those  produced  by  experiments  per- 
formed in  a  vacuum. 

In  many  instances,  the  agent  always  operates,  but  with 
very  different  degrees  of  intensity.  Here  its  influence 
may  frequently  be  ascertained  by  the  third  of  the  above 
principles.  Thus,  it  is  impracticable  to  produce  a  per- 
fect vacuum ;  yet  the  influence  of  the  atmosphere  may  be 
ascertained  from  observing  the  variations  in  the  bodies' 
motions,  as  the  density  of  the  resisting  medium  varies. 

In  searching  for  the  cause  of  a  known  phenomenon, 
we  are  often  aided  by  analogy,  as  like  effects  generally 
spring  from  like  causes.  But  we  should  guard  against 
the  erroneous  supposition  that  causes  resemble  their  ef- 
fects. There  is  nothing  in  a  musical  instrument  or  its 
motions  that  resembles  its  sounds,  nor  is  there  anything 
in  a  rose  resembling  its  odor  or  color ;  and  so  of  all  our 
senses.  Yet  this  error  has  prevailed  extensively,  owing 
partly  to  the  common  tendency  to  confound  cause  and 
effect,  and  partly  to  overlooking  the  wide  difference  be- 
tween direct  resemblance  and  corresponding  intensity. 
The  effect  generally  varies  as  the  intensity  of  the  cause : 
but  this  no  more  proves  resemblance  than  the  fact  that 
the  more  a  man  spends,  the  less  he  has,  proves  that  wealth 
resembles  poverty. 

Although  experiments  cannot  aid  us  directly,  in  as- 


SEC.  3.]  GENERAL  PRINCIPLES.  1*79 

cending  from  an  effect  to  its  cause,  yet  they  frequently 
enable  us  to  test  the  influence  of  a  possible  agent,  in  pro- 
ducing the  effect :  for  we  have  only  to  put  it  into  opera- 
tion, and  note  the  results.  Thus,  if  we  are  investigating 
the  origin  of  basaltic  columns,  we  may  take  some  of  the 
rock,  melt  it,  and  allow  it  to  cool  under  pressure.  If  we 
now  find  that  a  columnar  structure  results,  we  have  as- 
certained one  cause  which  may  have  produced  the  phe- 
nomenon in  question. 

A  single  experiment  of  this  kind,  however,  teaches  us 
only  that  such  an  agency  was  probably  the  cause,  except 
where  there  is  no  other  admissible  cause :  and,  therefore, 
it  generally  requires  repeated  experiments,  to  determine 
the  question.  Thus,  if  we  are  investigating  the  origin 
of  mineral  veins,  we  may  try  if  we  can  produce  such  phe- 
nomena from  aqueous  deposits.  When  this  experiment 
gives  a  negative  result,  we  may  try  chemical  precipita- 
tion. If  this  should  fail,  we  may  try  electro-galvanic 
agency :  and  if  this  fail,  we  may  try  the  influence  of  sev- 
eral agencies  combined. 

When  it  is  found  that  an  effect  is  not  produced  by  any 
known  cause,  it  must  be  attributed  to  some  new  kind  of 
agency,  whose  nature  is  to  be  ascertained  by  observation 
or  experiment  and  testing  hypotheses.  Here  we  must 
beware  of  adopting  an  agent  as  the  cause  without  con- 
clusive proof,  as  we  are  liable  to  assign  imaginary  causes, 
many  instances  of  which  occur  in  the  scholastic  philoso- 
phy. The  descent  of  heavy  bodies,  for  instance,  was  at- 
tributed to  a  natural  tendency  downward,  just  as  the 
phenomena  of  gravitation  have  been  more  recently  at- 
tributed to  a  natural  tendency  of  bodies  to  move  towards 
each  other,  whereas  no  such  thing  exists,  the  natural 
tendency  of  bodies  being  to  remain  as  they  are,  and  nei- 
ther to  move  nor  to  stop  moving,  except  as  they  are 
made  to  do  so. 

In  tracing  a  chain  of  causes,  the  easiest  course  gener- 
ally is,  to  ascertain  first  the  immediate  cause,  and  then 
the  remoter  causes  successively,  in  their  order.  Thus, 
the  real  motions  of  the  planets  are  the  immediate  cause 
of  the  phenomena  which  they  present  to  our  view.  Those 
being  determined,  the  next  point  was,  to  ascertain  the 
causes  of  these  motions ;  and  when  this  was  done,  the 
law  of  gravitation  still  remained  to  be  accounted  for. 
Supposing  it  should  be  traced  to  undulations  of  ether, 


180  CAUSES  AND  EFFECTS.  [CHAP.  X. 

we  might  still  inquire  fato  the  cause  of  these,  and  thus 
proceed,  till  we  came  to  the  direct  action  of  God,  which 
is  the  ultimate  efficient  cause  of  all  natural  phenomena. 

In  investigating  what  causes  would  produce  certain 
supposed  effects,  we  reason  from  intuitive  principles, 
combined  with  our  experience  as  to  what  causes  pro- 
duced precisely  similar  effects ;  and  the  course  of  pro- 
ceeding is  essentially  the  same  as  that  just  discussed. 
We  argue  on  the  principle  that  a  cause  which  has  pro- 
duced a  certain  effect,  will  produce  the  same  effect  again, 
if  operating  in  the  same  circumstances. 

In  ascertaining  the  effects  of  known  causes,  the  pro- 
cesses are  very  similar  to  the  preceding:  but  they  are 
generally  simpler,  and  the  aid  of  direct  observation  or 
experiment  is  frequently  more  extensive.  For,  as  the 
agents,  or  others  quite  similar,  generally  operate  within 
our  view,  we  can  observe  the  results,  whereas  the  causes 
of  many  visible  effects  have  long  ceased  to  operate,  and 
therefore  observation  may  be  unavailing.  Sometimes, 
again,  a  single  well-conducted  experiment  is  conclusive, 
as  an  agent  will  always  produce  what  it  has  once  pro- 
duced, in  the  same  circumstances,  while  the  fact  that  a 
certain  agent  produces  effects  precisely  similar  to  the  one 
in  question,  does  not  prove  that  this  did  not  spring  from 
an  agency  in  some  respects  widely  different. 

In  many  important  cases,  however,  experiments  are 
inadmissible  or  impracticable.  Thus,  we  can  rarely  test 
a  political  theory,  by  starting  a  community  organized  on 
its  principles ;  and  we  cannot,  without  imminent  danger 
of  sacrificing  life,  try  the  influence  of  powerful  newly  dis- 
covered medicines,  by  administering  them  experimental- 
ly. In  all  such  cases,  we  must  have  recourse  to  the  more 
indirect  methods  already  explained,  the  rules  for  testing 
effects  being  substantially  the  same  as  those  by  which 
we  ascertain  causes. 

Where  the  causes  in  question  have  ceased  to  act,  we 
may  observe  the  effects  of  perfectly  similar  causes  which 
still  operate ;  and,  if  none  such  exist,  we  must  extend  our 
observation,  and  apply  such  of  the  preceding  rules  as  are 
applicable  to  the  nature  and  circumstances  of  the  case. 

The  fact  that  similar  causes  generally  produce  similar 
effects,  often  aids  us  in  determining  the  effect  of  a  cause 
similar  to  one  whose  effects  are  already  known.  But 
the  same  caution  is  requisite  here  as  in  the  case  of  the 


SEC.  3.]  TRACING  EFFECTS.  181 

converse  principle  stated  above :  for  there  are  numerous 
exceptions.  Thus,  not  only  do  different  degrees  of  heat 
sometimes  produce  very  different  effects,  but  those  of  a 
freezing  cold  strongly  resemble  a  burn. 

Where  an  agent  produces  several  distinct-  effects,  inde- 
pendent of  each  other,  every  one  of  them  may  be  studied 
as  if  it  were  the  sole  effect,  without  any  reference  to  the 
others :  and  this  course  is  frequently  requisite,  in  order 
to  avoid  confusion,  and  to  obtain  a  correct  and  extensive 
knowledge  of  the  particular  phenomenon  under  consider- 
ation. 

In  many  instances,  the  various  effects  are  directly  con- 
nected with  each  other,  and  re-act  on  their  causes,  as  in 
cases  of  many  moral  and  political  agencies.  Here  it  is 
requisite  to  take  a  wide  view  of  the  subject,  in  order  to 
obtain  a  just  and  adequate  knowledge  of  it.  We  should 
first  acquire  an  accurate  knowledge  of  all  the  phenome- 
na, considered  simply  as  such,  and  then  apply  the  proper 
principles,  in  order  to  discover  their  mutual  relations  and 
connections.  We  must  not  infer  that  the  same  cause 
which  produces  an  effect  in  one  case,  may  not  be  the  re- 
sult of  this  effect  in  another.  Penury  sometimes  pro- 
duces vice;  but  vice  more  frequently  produces  penury. 
Wherever  we  can  discover  a  primary  cause,  we  should 
first  ascertain  its  original  effect,  then  trace  the  reciprocal 
influence  exerted  on  it  by  this  effect,  and  afterwards  in- 
quire how  the  latter  is  re-affected  by  wrhat  it  has  itself 
produced. 

In  all  inquiries  regarding  causes  and  effects,  we  should 
ascertain  the  real  character  of  the  thing  which  we  as- 
sume as  known^:  else  we  shall  either  fall  into  error  or 
lose  our  labor.  *  Thus,  if  we  assume  that  a  bad  law  is 
good,  and  then  try  to  trace  its  effects,  we  shall  undoubt- 
edly arrive  at  an  erroneous  conclusion ;  or  if  we  attempt 
to  discover  why  nature  abhors  a  vacuum,  or  why  swal- 
lows can  live  under  water  during  winter,  we  shall  cer- 
tainly labor  in  vain,  because  our  assumptions  are  false. 
Effects  which  never  existed  can  have  no  causes ;  and  im- 
aginary causes  can  produce  no  effects. 

So  we  should  rote  and  bear  in  mind  the  particular  ob- 
ject of  our  investigation,  and  not  confound  an  inquiry 
into  causes  with  one  into  effects,  or  one  into  the  imme- 
diate with  one  into  the  ultimate  cause. 


182  LANGUAGE.  [CHAP.  XI. 


CHAPTER  XL 

OF  LANGUAGE. 

§  1.  ORIGIN  AND  PROGRESS  OF  LANGUAGE. — Causes  of  Language. — 
Its  two  primary  Sources. — Its  further  Progress. — Formation  of  va- 
rious Parts  of  Speech. — Modes  of  enlarging  the  stock  of  Words. — 
Foreign  and  vernacular  Roots. — Origin  of  different  Significations 
of  the  same  Words. — Apparent  and  real  Derivatives. — Origin  of 
the  Diversity  of  Languages. — Language  not  of  Divine  Formation. 
— Importance  of  knowing  its  Origin. 

MAN  is  very  superior  to  all  the  lower  animals  in  the 
power  of  vocal  expression,  while  he  surpasses  them  still 
more  in  the  extent  and  vigor  of  his  thinking  faculties. 
These  appear  to  be  the  causes  that  have  raised,  on  a 
very  narrow  foundation,  a  system  of  phonetic  expression 
which,  even  among  the  rudest  of  the  human  race,  incom- 
parably excels  anything  found  among  the  lower  creation. 
If  we  compare  the  highest  attainments  of  a  parrot  with 
what  a  child  effects  by  his  own  unaided  eiforts,  we  shall 
have  a  striking  proof  of  man's  superiority :  and  if  we 
further  notice  the  ingenuity  with  which  the  dumb  com- 
municate their  thoughts  to  each  other,  without  any  train- 
ing, we  shall  readily  understand  the  manner  in  which 
spoken  language  must  have  originated,  and  infer  that  it 
is  a  natural  result  of  our  circumstances  and  faculties. 

Man  expressed  all  his  strong  emotions  and  desires  by 
peculiar  instinctive  ejaculations,  and  also  imitated  the 
various  sounds  that  he  heard.  From  these  two  sources 
have  sprung  all  spoken  language.  When  we  examine 
even  the  most  copious  original  language,  such  as  the  An- 
cient Greek,  we  easily  trace  its  myriads  of  words  to  a  few 
hundred  roots,  which  give  manifest  indications  of  their 
origin.  Such  words  as  eat,  laugh,  moan,  groan,  hiss, 
buzz,  hum,  crash,  crush,  rush,  crow,  roar,  low,  snarl,  hurl, 
gurgle,  murmur,  purl,  coo,  cackle,  snap,  slap,  rap,  cut, 
babble,  hop,  strike,  bull,  bee,  drum,  horse,  cuckoo,  &c.,  &c., 
evidently  originated  in  onomatopoeia,  or  an  imitation  of 
natural  sounds.  Most  actions  are  accompanied  by  cer- 
tain sounds,  an  imitation  of  which  would  form  the  verbs 


SEC.  1.]  ITS  ORIGIN  AND  PROGRESS.  183 

employed  to  signify  them.  So  the  original  names  of  an- 
imals would  consist  either  of  an  imitation  of  their  own 
cries  or  of  the  instinctive  exclamations  uttered  on  first 
beholding  them. 

It  will  not  admit  of  a  doubt  that  man  would  soon  dis- 
cover his  extensive  powers  of  vocal  expression  ;  and  the 
rapidity  and  precision  with  which  he  could  thus  com- 
municate his  thoughts  could  not  long  escape  his  atten- 
tion. This  would  lead  to  the  constant  use  of  those 
sounds,  by  the  head  of  the  family,  to  denote  the  objects 
and  actions  which  they  were  employed  to  express  in  the 
first  instance ;  and  the  other  members  of  the  household 
would,  of  course,  adopt  his  expressions.  Proper  nouns, 
or  names  originally  applied  to  individual  objects,  would 
be  generalized  by  being  applied  to  all  things  of  the  same 
kind,  just  as  children  call  every  horse  or  ox  by  the  names 
of  their  fathers'. 

Language  being  thus  started,  it  would  gradually  be 
extended  and  improved,  in  various  ways.  At  first  it 
would  be  much  assisted  by  gestures  and  expressions  of 
the  countenance :  but  as  it  became  more  copious,  these 
would  fall  into  disuse,  except  to  give  it  force  and  vivac- 
ity. 

The  same  words  would  be  frequently  used  to  denote 
both  objects  and  actions ;  or,  in  the  language  of  gram- 
marians, they  would  be  employed  both  as  nouns  and  as 
verbs,  a  practice  of  which  we  have  still  many  instances, 
as  feed,  drink,  touch,  feel,  smell,  taste,  love,  hate,  hope, 
fear,  earth,  air,  fire,  water,  and  light.  Which  was  the 
earlier  use  is  a  question  of  little  consequence.  Many 
words  Avere  probably  used  in  both  significations  from 
the  first,  while  in  some  cases  the  verbal  sense  probably 
had  precedence,  and  in  others  the  nominal. 

Adjectives  arose  from  using  participles  or  the  names 
of  actions  and  objects  to  denote  qualities,  a  practice  still 
common.  Thus,  we  speak  of  a  "straight"  (that  is  stretch- 
ed) line,  a  "  brick"  house,  a  "  sea"  bird,  "  iron"  strength, 
and  so  forth.  In  many  instances,  the  form  of  the  word 
was  changed,  to  correspond  with  the  different  significa- 
tions, the  older  being  generally  retained  for  the  quality. 
Thus  a  "  red"  color  is  a  "  roe"  color,  and  "  ten"  men  is 
"  toes"  men,  as  we  shall  readily  see  by  referring  to  the 
corresponding  German  and  Saxon  terms.  In  other  cases, 
the  original  meaning  was  entirely  lost ;  and  it  now  ap- 


184  LANGUAGE.  [CiiAr.  XL 

pears  as  a  noun  or  a  verb  only  in  some  kindred  language. 
Thus,  we  have  the  origin  of"  strong"  in  the  Latin  string, 
stretch  or  strain ;  and  the  source  of  weak  is  found  in 
vino  (past  vie),  subdue  or  overcome.  So  we  find  the  or- 
igin of  green  in  the  Latin  gramen,  grass. 

Interjections  are  a  part  of  instinctive  language,  and 
must,  therefore,  have  been  nearly  as  numerous  in  the  ear- 
liest times  as  they  are  now. 

Adverbs  Avere  originally  phrases,  adjectives  or  parti- 
ciples, of  which  they  still  exhibit  many  indications.  Thus 
to-day  is  simply  this  day,  as  the  corresponding  Latin  ho- 
die  is  only  hoc  die  (this  day).  The  same  remark  applies 
to  prepositions  and  conjunctions,  although  several  of 
these  were  originally  pure  verbs,  as  some  of  them  are 
still,  such  as  except  and  suppose. 

The  advantages  of  distinguishing  the  speaker  and  the 
person  addressed  or  spoken  of,  are  so  great  and  obvious 
that  the  personal  pronouns  must  be  nearly  as  old  as  the 
first  origin  of  language.  Yet  they  probably  sprung  from 
nouns,  participles  and  adjectives,  as  we  may  infer  from 
the  abridgements  which  they  have  undergone,  since  the 
period  of  the  earliest  written  compositions. 

In  enlarging  the  stock  of  words  otherwise  than  by  the 
original  processes,  arbitrary  terms,  entirely  new,  were 
rarely  introduced,  since  they  would  sound  strange,  and 
furnish  no  key  to  their  own  signification.  Instead  of 
this,  other  methods  were  adopted.  Old  words  were 
gradually  changed  in  pronunciation,  till  several  sprung 
from  one;  and  the  different  forms  which  thus  arose, 
were  used  to  designate  different  modifications  of  the 
same  thing,  each  form  being  appropriated  to  what  it  was 
thought  to  express  with  most  precision.  Thus,  a  child 
squalls,  and  a  pig  squeals  ;  an  owl  screeches  /  a  person 
suddenly  frightened  shrieks  /  and  a  woman  in  great  pain 
screams.  In  some  cases,  instead  of  changing  the  old 
word  directly,  it  was  adopted  from  another  language,  in 
its  altered  form,  with  a  new  but  kindred  signification. 
Thus,  the  winds  blow,  and  the  waters  flow.  The  latter 
word  is  directly  from  the  Latin ;  but  it  sprung  from  the 
same  root  as  the  former.  So  aur-ist  is  only  a  Graeco- 
Latin  form  of  ear  doctor. 

A  more  fertile  source  of  additions,  at  least  in  the  more 
cultivated  languages,  was  the  practice,  still  common,  of 
uniting  two  or  more,  to  form  one  word.  Here  the  new 


SEC.  1.]  ITS  ORIGIN  AND  PROGRESS.  185 

meaning  is  a  modification  of  the  thing  denoted  by  the 
principal  compounding  term,  which  is  particularly  indi- 
cated by  the  other  word.  Thus,  in  the  word  bookseller^ 
the  last  syllable  is  the  principal  root,  or  that  which  de- 
notes the  object  meant.  Er  is  an  abridgement  of  the 
old  word  icer,  a  man,  so  that  sett-er  is,  a  man  who  sells, 
and  booJc-sell-er,  a  man  who  sells  books. 

The  compounding  terms,  instead  of  being  adopted 
from  the  vernacular,  were  often  taken  from  some  for- 
eign language.  This  frequently  rendered  the  meaning 
of  the  compound  much  more  definite,  especially  in  ab- 
stract terms,  or  such  as  express  a  great  variety  of  things. 
For,  as  the  compounding  terms  were  unfamiliar,  the  act- 
ual signification  of  the  compound  depended  mainly  on 
the  definition,  and  therefore  its  exact  import  was  not 
readily  mistaken,  so  that  a  word  formed  in  this  way  was 
equivalent  to  the  invention  of  an  entirely  new  term. 
Compounds  formed  from  vernacular  words,  on  the  other 
hand,  directly  suggest  a  meaning,  independently  of  any 
definition,  which  is  often  considered  unnecessary,  in  such 
cases.  But  the  literal  signification  of  the  compounding 
words  is  frequently  different  from  the  true  one,  especial- 
ly in  technical  and  scientific  terms ;  and  hence  will  arise 
obscurity  and  error,  unless  we  attend  to  the  actual,  and 
not  to  the  etymological  sense. 

To  illustrate  this  difficulty,  we  may  observe  that  Ge- 
ometry literally  signifies  land-measuring,  Geography,  a 
description  of  the  Earth,  and  Geology,  a  discourse  about 
the  Earth,  so  that,  if  we  look  only  to  the  etymologies, 
we  should  be  quite  misled  regarding  the  first,  and  we 
could  not  distinguish  the  second  from  the  third.  So 
Astrology,  etymologically  considered,  is  a  more  proper 
term  for  what  is  called  Astronomy,  as  the  former  liter- 
ally signifies  the  science  of  the  heavenly  bodies,  and  the 
latter,  only  the  science  of  their  laws.  Alchemy  and 
Chemistry  are  only  different  forms  of  the  same  word ; 
yet  their  real  meanings  differ  as  much  as  those  of  the 
two  preceding  terms. 

Owing  to  the  difficulty  and  inconvenience  of  forming 
new  terms,  various  significations  were  frequently  attach- 
ed to  the  primary  import  of  many  words,  without  their 
undergoing  any  change.  A  common  instance  of  this 
was,  employing  words'  which  originally  meant  physical 
objects  to  denote  impalpable  things,  to  which  they  were 


186  LANGUAGE.  [CHAP.  XI. 

believed  to  bear  some  analogy.  Thus,  the  same  Hebrew 
word  denotes  both  wind  and  spirit  •  and  the  Latin  ani- 
mus, mind,  and  anima,  soul,  are  evidently  identical  with 
the  Greek  anemos,  wind.  So  investigate  originally  meant 
to  track,  and  ponder,  to  weigh.  As  objects  of  sense  first 
received  names,  because  they  first  excited  attention,  those 
of  all  others  originated  chiefly  in  this  manner,  although 
the  primary  significations  are  now  found,  in  many  in- 
stances, only  in  other  languages. 

Words  and  expressions  were  frequently  employed  fig- 
uratively, to  denote  things  which  bore  some  real  or  fan- 
cied resemblance  or  relation  to  the  original  significations, 
and,  in  many  instances,  this  usage  prevailed  so  extensive- 
ly that  the  new  meanings  became  as  familiar  as  the  pri- 
mary, so  that  the  original  metaphor  disappeared.  Thus 
a  "  hard-hearted"  man  is  not  considered  a  figurative  ex- 
pression, any  more  than  a  hard  rock. 

Sometimes  the  new  significations  entirely  superseded 
the  originals ;  and,  not  unfrequently,  a  third  was  ingraft- 
ed on  the  former,  which  bore  no  resemblance  to  the  lat- 
ter. Thus,  the  word  virtue  originally  signified  manli- 
ness, being  taken  from  vir,  a  man — then,  bravery,  because 
that  is  a  manly  quality — and,  finally,  any  good  quality, 
so  that  we  speak  of  the  virtues  of  drugs  and  plants.  By 
this  means  the  same  word  sometimes  came  to  have  con- 
trary significations.  The  Latin  sacer  means  both  holy 
and  accursed,  the  original  signification  being  set  apart  or 
separated. 

When  the  vocabulary  of  a  language  had  thus  become 
comparatively  copious,  figurative  expressions  became  less 
common ;  and  the  general  style  became  more  precise  and 
literal,  because  there  was  less  occasion  for  metaphors, 
while  the  more  extensive  application  of  language  for  di- 
dactic purposes  rendered  perspicuity  and  precision  more 
desirable. 

Words  not  primitive  are  usually  divided  into  com- 
pound and  derivative:  but  there  is  generally  no  real 
etymological  diiference;  for  most  derivatives  are  only 
compounds  of  which  the  subordinate  compounding  terms 
no  longer  appear  separately  in  the  language.  These  are 
generally  found,  however,  either  in  its  older  forms  or  in 
other  languages.  Thus  the  affix  er  is  the  Saxon  wer,  a 
man,  so  that  hunter  is,  in  reality,  a  compound  as  much 
as  huntsman  ;  and  the  common  prefix  in  or  un,  signify- 


SEC.  1.]  ITS  ORIGIN  AND  PROGRESS.  187 

ing  not,  occurs  in  Hebrew  as  a  distinct  word,  with  the 
same  sense. 

Sometimes  prefixes  and  affixes  are  only  common  terms 
slightly  altered.  Begird  is  by-gird  or  gird  round ;  -mis- 
pronounce is  miss-pronounce  ;  and  manly  is  man-like. 

The  real  derivatives  of  a  language  are,  the  various  new 
forms  of  a  word,  employed  to  denote  several  modifica- 
tions of  the  same  thing :  but  as  it  is  difficult  to  trace  the 
derivation,  in  such  cases,  grammarians  have  frequently 
considered  all  the  forms  primitive  words. 

Different  communities  pronounced,  compounded,  and 
contracted  words  variously,  and  employed  different  new 
terms  to  denote  the  same  thing,  while  each,  in  many  in- 
stances, superinduced  peculiar  new  meanings  on  the  pri- 
mary. Striking  differences  arose,  also,  from  some  races 
amalgamating  modifying  words  with  the  principal  terms 
in  pronunciation,  such  as  personal  pronouns  with  the 
verbs  of  which  they  were  nominatives,  and  personal  pro- 
nouns and  prepositions  with  the  nouns  which  they  qual- 
ified. Hence  originated  numerous  inflections,  as  in  Latin 
and  Greek,  while  other  races,  as  the  Chinese,  always  kept 
the  words  distinct,  whence  their  languages  exhibit  hard- 
ly any  inflections.  Other  differences  arose  from  figura- 
tive or  poetical  expressions  superseding,  in  some  lan- 
guages, the  original  terms  which  others  retained. 

When  wo  further  consider  the  wide  diversity  in  the 
circumstances  of  communities,  and  in  the  objects  with 
which  they  were  conversant,  the  great  variety  of  lan- 
guages which  is  found  throughout  the  world,  appears 
only  a  natural  consequence  of  these  numerous  causes  of 
divergence.  If  we  observe  the  rapidity  with  which  a 
copious  language  has  run  into  several,  within  the  period 
of  authentic  history,  we  can  easily  understand  how  quick- 
ly a  language,  yet  rude  and  barren,  might  run  into  many, 
while  the  art  of  writing  was  unknown,  and  communities 
were  very  small.  A  patriarch,  living  alone  with  his  fam- 
ily, would  communicate  to  them  his  own  linguistic  pe- 
culiarities ;  and  these  would  increase,  more  or  less,  with 
every  successive  generation,  more  especially  if  every  one 
of  the  sons  separated  from  the  common  parent,  and  held 
little  further  intercourse  with  his  kindred,  as  would  very 
frequently  happen  in  early  ages  when  the  greatest  part 
of  the  world  was  yet  uninhabited.  It  may  further  be 
observed  that  the  names  of  things  which  vanished  from 


188  LANGUAGE.  [CHAP.  XL 

sight  would  be  forgotten,  while  new  terms  would  be 
used  to  denote  new  objects. 

When  a  language  has  become  copious,  assumed  a 
definite  form,  and  been  reduced  to  writing,  subsequent 
changes  of  the  old  elements  and  constructions  may  be 
very  slow,  although  it  may  receive  a  host  of  new  words. 
Hence  those  languages  which  sprung  from  a  common 
source,  at  periods  long  subsequent  to  the  general  dis- 
persion of  mankind,  frequently  resemble  each  other  very 
closely,  while  those  which  separated  much  earlier  often 
retain  such  faint  traces  of  their  original  unity  that  this  is 
established  only  by  means  of  the  intermediate  languages, 
which  serve  as  connecting  links. 

We  are  told,  in  the  Holy  Scriptures,*  that  God  brought 
the  animals  to  Adam,  in  order  that  he  might  name  them, 
and  that  whatever  Adam  called  every  species  became  its 
name.  Now  animals  would  excite  attention  before  any 
other  object ;  and  when  language  had  once  originated 
by  giving  them  names,  there  was  no  occasion  for  miracu- 
lous aid  to  continue  the  process  thus  begun.  The  mea- 
ger foundations  on  which  language  is  built,  the  numer- 
ous and  palpable  marks  of  onomatopoeia  which  it  still 
displays,  the  absence  of  terms  originally  denoting  any 
mental  or  immaterial  objects,  and  the  many  defects  with 
which  it  abounds,  and  which  are  particularly  observable 
in  its  most  ancient  forms,  show  that  it  is  o£  human,  and 
not  of  Divine,  origin. 

The  Almighty  would  not  encourage  mental  inactivity 
by  conferring  miraculously  what  he  gave  us  faculties  for 
forming  in  a  natural  way.  Nor  is  it  credible  that  he 
would  act  thus  when  the  gift  was  soon  to  be  lost  irre- 
coverably, and  superseded  by  a  multitude  of  rude  lan- 
guages, precisely  such  as  mankind  would  readily  have  in- 
vented, without  any  miraculous  aid. 

A  correct  view  of  the  origin  and  progress  of  language 
is  requisite,  in  order  that  we  may  use  it  aright  ourselves, 
and  properly  interpret  the  expressions  of  others  :  for  er- 
rors on  this  subject  produce  fallacious  rules  both  of  in- 
terpretation and  of  composition.  The  fiction  of  the  Di- 
vine origin,  and  consequently  primitive  perfection,  of  lan- 
guage, repels  scrutiny,  misleads  the  grammarian,  and 
tends  strongly  to  produce  and  foster  the  common  error 
that  language  is  a  correct  representation  of  nature,  and 
*  Genesis,  Chapter  ii.,  verses  19  and  20. 


SEC.  2.]  ITS  USES.  189 

that  we  can  discover  truth  by  the  study  of  mere  expres- 
sions. 

§2.  USES  OF  LANGUAGE. — Uses  and  Defects  of  "natural"  Lan- 
guage.— Original  object  and  superiority  of  Speech. — Its  other  Ad- 
vantages.— Use  of  General  Terms. — Requisites  to  the  proper  ex- 
pression of  Thought. — First  Rule.  —  Common  Violation  of  it. — 
Different  styles  of  didactic  and  emotional  compositions. — Compre- 
hension and  Extension  of  Terms. — Second  Rule. — Sources  of  Am- 
biguity.— Third  Rule. — Common  Errors. — Means  of  testing  the 
amount  of  our  Knowledge  of  a  subject,  and  of  avoiding  Vagueness 
and  Obscurity  of  Expression. — Verbal  and  Real  Definitions. — Why 
the  former  only  belong  to  Logic. — Three  Rules  regarding  them, 
with  Remarks.  —  General  characteristics  of  good  Definitions.  — 
When  new  Terms  may  be  rightly  employed. — Ordinary  Practice. — 
Foreign  and  Vernacular  Roots. — Evils  of  introducing  new  Terras 
unnecessarily. — Origin  of  many  new  Terms. 

Gestures,  expressions  of  the  countenance,  and  instinct- 
ive exclamations,  which  have  been  termed  "natural"  lan- 
guage, bear  the  same  relation  to  speech  that  pictures  do 
to  phonetic  writing ;  and  hence  they  are  very  service- 
able in  exciting  the  passions.  But  they  are  incapable  of 
expressing  many  thoughts  at  all,  and  others  they  express 
only  vaguely,  while  their  power  of  exciting  emotion  is 
positively  unfavorable  to  them,  as  a  means  of  communi- 
cating knowledge,  since  disturbing  emotions  are  fertile 
sources  of  error. 

The  original  object  of  speech  was,  simply  to  express 
or  communicate  thought:  and  vocal  language  possesses 
over  every  other  means  the  advantages  of  much  greater 
precision  and  rapidity  of  communication.  Even  if  we 
could  invent  manual  or  other  inaudible  signs,  to  denote 
every  thought,  there  are  none  that  could  be  communi- 
cated so  rapidly  as  vocal  signs  or  words.  Nor  could 
man  have  invented  such  signs  without  the  previous  as- 
sistance of  words,  as  otherwise  many  of  the  requisite 
signs  could  not  be  agreed  on. 

It  is  by  means  of  words  alone  that  the  attainments  of 
one  person  or  generation  can  be  satisfactorily  communi- 
cated to  another,  and  mankind  be  both  benefited  by  the 
experience  or  labors  of  their  predecessors  or  contempo- 
raries, and  enabled  to  add  to  their  acquisitions. 

Speech  is  also  employed,  in  a  written  form,  to  aid  us 
both  in  our  original  researches  and -in  retaining  our  ac- 
quisitions. For  we  cannot  generally  follow  out  a  long 
and  intricate  train  of  reasoning,  without  assisting  the 


190  LANGUAGE.  [CHAP.  XI. 

Memory  by  written  symbols,  which  could  never  have 
been  brought  to  any  degree  of  perfection  without  the  pre- 
vious use  of  words.  But,  by  means  of  written  speech, 
we  can  clearly  express  every  step  of  the  most  intricate 
and  subtle  process ;  and  thus  we  can  easily  retrace  our 
steps,  whenever  we  wish  either  to  recall  something  which 
we  have  forgotten,  or  to  test  the  accuracy  of  certain  prop- 
ositions, by  a  deliberate  examination  of  the  various  proc- 
esses through  which  they  have  been  professedly  estab- 
lished, so  that  none  of  them  may  be  overlooked.  ' 

The  aid  of  language  is  requisite  to  retain  even  a  frag- 
ment of  our  former  acquisitions,  in  such  a  manner  that 
we  are  safe  from  error :  for  we  are  liable  to  forget  our 
former  conclusions,  as  well  as  the  processes  by  which  we 
arrived  at  them,  so  that  we  readily  mistake  them  for 
others  which  they  resemble,  and  thus  confound  what  we 
established  with  what  we  only  heard,  read,  or  imagined. 

Language  greatly  aids  reasoning  and  remembrance,  by 
means  of  comprehensive  and  general  terms.  Even  such 
simple  expressions  as  hope  and  fear  imply  things  which 
the  Memory  could  not  easily  retain,  without  the  aid  of 
language,  and  much  more  will  this  remark  apply  to  such 
terms  as  duty,  law,  and  government,  which  distinguish 
the  things  denoted  by  them  from  others  with  which  they 
would  be  confounded,  but  for  the  aid  of  expressions 
showing  the  very  things  meant.  Such  terms  are  also 
requisite  in  the  higher  kinds  of  generalization,  that  we 
may  be  able  to  remember  and  reason  regarding  preced- 
ing results :  and  they  also  enable  us  to  reason  upon  as- 
sumptions regarding  things  of  which  we  can  have  no 
idea,  such  as  indefinitely  small  quantities,  or  even  things 
which  cannot  exist,  as  the  square  roots  of  negative  quan- 
tities. 

In  order  to  express  our  thoughts  aright,  we  must  pos- 
sess a  knowledge  both  of  the  subject  and  of  the  language 
we  employ:  and  when  these  prerequisites  have  been  ac- 
quired, the  observance  of  the  three  following  rules  will 
secure  proper  expression. 

1  We  should  say  precisely  what  ice  mean.  It  is  not 
sufficient  to  avoid  expressions  totally  wide  of  our  mean- 
ing we  must  beware  of  saying  either  more  or  less  than 
we  intend.  Terms  may  be  either  too  general,  and  thus  in- 
clude something  which  ought  to  be  omitted ;  or  they  may 
be  too  particular,  and  consequently  omit  something  which 


SEC.  2.]  RULES  OF  EXPRESSION.  191 

ought  to  be  included.  In  mere  illustrations,  and  in  com- 
positions designed  to  excite  emotion,  it  is  often  proper 
to  employ  terms  more  particular  than  truth  would  war- 
rant :  but  in  purely  scientific  or  didactic  discourse,  this 
should  be  avoided,  because  the  more  general  expressions 
are  the  more  extensive  and  concise. 

Particular  terms  express  more  qualities  of  the  thing 
meant ;  and  hence  their  superiority  for  emotional  and  il- 
lustrative purposes.  "  Horse"  expresses  more  qualities 
than  "  quadruped,"  and  the  latter,  many  more  than  "  ani- 
mal." The  more  species  a  term  embraces,  the  fewer 
qualities  it  denotes,  and  conversely.  The  number  of 
qualities  a  word  expresses  is  termed  its  comprehension, 
and  the  number  of  individuals  or  species  that  it  indicates, 
its  extension.  These  two  evidently  vary  inversely ;  the 
wider  the  one,  the  narrower  the  other. 

2.  Our  expressions  should  not  be  ambiguous.  We 
should  reject  expressions  which  admit  of  two  or  more 
significations,  without  violating  any  just  rule  of  interpre- 
tation. Expressions  are  ambiguous,  either  where  one  or 
more  of  the  terms  bears  several  significations,  and  the 
context  does  not  determine  which  is  intended,  or  whero 
a  phrase  is  susceptible  of  various  grammatical  construc- 
tions. 

a.  Oar  expressions  should  be  perspicuous.  In  order  to 
this,  we  must. avoid  those  expressions  of  which  the  exact 
signification  cannot  be  detected  without  difficulty.  We 
are  liable  to  employ  words  of  whose  signification  we 
have  no  clear  notion,  without  ever  being  aware  of  our 
doing  so,  because  they  are  familiar  to  our  ears ;  and  thus 
we  are  apt  to  overestimate  our  knowledge  of  the  sub- 
ject. One  of  the  best  means  of  testing  the  amount  of 
this  is,  to  write  down  what  we  know,  in  terms  which  are 
perfectly  clear  and  unambiguous,  and  which  will  give 
any  person  of  ordinary  perspicacity  a  correct  notion  of 
what  is  meant.  The  application  of  this  test  will  show 
that  we  are  apt  to  mistake  a  familiarity  with  words  for 
a  knowledge  of  what  they  denote,  two  things  widely  dif- 
ferent. 

In  order  to  secure  perspicuity,  we  must  not  employ  an 
expression  without  knowing  precisely  what  we  under- 
stand by  it ;  and  when  we  are  obliged  to  use  one  that  is 
obscure,  ambiguous  or  not  well  known,  we  should  clear- 
ly fix  the  sense  in  which  we  employ  it,  either  by  the  form 
of  the  expression  or  by  a  definition. 


192  LANGUAGE.  [<UHAP.  XL 

Definitions  are  either  verbal  or  real.  The  former  point 
out  what  terras  denote  certain  things,  which  they  assume 
that  we  know ;  the  latter  unfold  the  nature  of  the  things 
denoted  by  certain  terms.  If  we  are  told  that  "  blue  is, 
the  color  of  the  sky,"  this  is  a  verbal  definition,  and 
teaches  nothing  unless  we  know  what  the  color  of  the 
sky  is.  But  if  we  are  told  that "  a  dial  is  an  instrument 
for  measuring  time,  by  means  of  the  different  directions 
in  which  a  shadow  falls,  throughout  the  day ;  and  it  con- 
sists of  a  flat  surface,  marked  with  the  hours,  and  a 
style  or  axis,  for  projecting  the  shadow" — this  is  a  real 
definition,  which  would  give  us  a  notion  of  what  a  dial 
is,  if  we  had  never  seen  or  heard  of  such  a  thing  before. 

Definitions  written  for  our  own  use  exclusively  will  be 
verbal,  since  they  are  designed  merely  to  aid  us  in  re- 
membering the  meaning  of  words,  or  the  sense  we  at- 
tach to  them.  We  cannot  give  a  real  definition  of  a 
thing  of  which  we  are  ignorant :  and  when  we  know  the 
thing,  the  object  of  a  definition  for  our  own  use  cantonly 
be,  to  remind  us  of  the  term  by  which  it  is  designated. 
Hence  the  subject  of  real  definitions  belongs  to  Educa- 
tion or  Rhetoric,  and  not  to  Logic. 

The  following  are  the  principal  rules  regarding  verbal 
definitions. 

1 .  The  definition  should  be  free  from  the  difficulties 
which  it  is  designed  to  obviate  or  remove,  and  accord 
with  the  rides  of  correct  expression.     If  it  is  inaccurate, 
ambiguous,  obscure,  or  couched  in  terms  partly  unknown, 
it  is  worse  than  useless,  since  it  misleads,  while  it  pro- 
fesses to  guide.     A  common  violation  of  this  rule  is,  to 
employ  defining  terms  which  are  as  unintelligible  as  the 
word  defined,  so  that  the  definition  is  tantamount  to  say- 
ing a  thing  is  what  it  is.     Thus,  life  has  been  defined  "  a 
system  of  vital  forces,"  that  is — "a  system  offerees  per- 
taining to  life."     So,  justice  is  defined,  in  the  Institutes 
of  Justinian,  "  a  constant  and  perpetual  desire  to  give 
every  one  his  right,"  which  is  equivalent  to  saying  that 
"justice  is,  a  desire  to  do  justice  to  every  one,"  since  a 
man's  right  requires  to  be  defined  as  much  as  his  just 
due. 

2.  The  thing  defined  should  be  clearly  pointed  out,  and 
distinguished  from  all  others.     In  order  to  this,  the  defi- 
nition  must   express  the  peculiar  characteristic  of  the 
thing  defined,  and  exclude  that  of  every  other  being. 


SEC.  2.]  DEFINITIONS.  193 

Consequently  every  negative  definition  violates  the  first 
part  of  this  rule,  since  it  never  tells  us  what  a  thing  is, 
but  only  what  it  is  not ;  and  every  definition  which  ap- 
plies equally  to  other  things,  violates  the  second  part  of 
the  rule.  It  is  not  a  proper  definition  of  a  man,  to  say 
that "  he  is  not  a  fish,"  as  this  includes  every  being  ex- 
cept fishes,  while  it  wholly  fails  to  tell  us  what  man  is. 
So,  the  definition  "man  is  a  rational  being,"  violates  the 
rule ;  for  so  are  angels. 

3.  The  definition  should  comprise  the  ivhole  of  the 
thing  defined,  and  not  merely  a  part  of  it:  otherwise  it 
is  defective.  It  is  not  a  proper  definition  of  ruminants , 
to  say  that  "  they  are  sheep  and  oxen  ;"  for  goats,  deer, 
antelopes  and  camels  also  belong  to  that  order.  Nor  is 
it  a  proper  definition  of  sioans  to  say  that  "they  are 
large,  white  birds,  of  the  order  natatores  or  swimmers ;" 
for  this  excludes  the  black  swans.  This  rule  is  very  apt 
to  be  violated  wherever  our  views  of  the  subject  defined 
are  too  narrow,  since  our  attention  is  apt  to  be  confined 
to  that  with  which  we  are  familiar,  so  that  we  overlook 
the  rest,  although  this  may  possibly  be  the  largest  and 
most  important  part. 

A  proper  definition  requires  both  a  good  knowledge 
of  the  subject  and  care  in  forming  it.  Hence  our  defini- 
tions generally  improve  as  our  knowledge  of  the  subject 
becomes  more  extensive,  and  further  examination  and  ex- 
perience gradually  show  the  imperfections  of  former  def- 
initions. 

Many  definitions  can  generally  be  given  of  the  same 
expression ;  and  the  best  is,  that  which  gives  the  most 
correct  notion  of  its  import  to  the  party  for  whom  it  is 
intended.  Hence  definitions  designed  for  our  own  use 
should  be  such  as  are  most  satisfactory  to  ourselves,  al- 
though they  might  not  be  suitable  for  others.  We 
should,  however,  depart  from  the  ordinary  signification 
of  terms  as  little  as  a  regard  to  clearness  and  precision 
will  permit,  since  difficulty  and  error  are  very  apt  to 
arise  from  affixing  peculiar  meanings  to  terms.  But 
when  we  are  obliged  to  employ  a  vague  term,  we  should 
either  define  or  distinctly  note  the  particular  sense  in 
which  we  employ  it :  otherwise  obscurity  or  error  will 
probably  result. 

When  there  is  no  term  in  the  language  to  denote  the 
meaning,  without  great  risk  of  error,  the  best  way  is,  to 


194  LANGUAGE.  [CHAP.  XL 

adopt  a  new  word.  This  is  generally  desirable  where  a 
new  name  is  required  for  something  essentially  different 
from  anything  which  already  has  a  name  in  the  language : 
for,  to  attach  the  new  meaning  to  some  old  term  would 
lead  to  confounding  the  various  significations,  a  thing 
which  has  been  a  fertile  source  of  error. 

Sometimes  it  is  requisite  only  to  borrow  a  word  from 
a  foreign  language,  and  modify  its  form,  if  necessary. 
In  other  cases,  we  must  coin  a  new  term.  It  has  been  a 
common  practice  to  form  a  compound  from  Latin  or 
Greek  roots,  adhering  to  the  proper  rules  of  composition 
or  derivation.  The  latter  language  is  generally  prefera- 
ble, because  it  is  more  unlike  the  vernacular.  Where  the 
thing  can  bo  expressed  exactly  by  vernacular  roots,  these 
should  be  adopted  in  preference,  since  the  compounding 
terms  directly  suggest  the  signification  of  the  word. 
Compounds  of  this  kind  are  generally  better  for  emotion- 
al purposes,  as  they  affect  the  feelings  more  strongly: 
but  they  are  frequently  objectionable  for  didactic  pur- 
poses, as  they  tend  to  mislead  us  regarding  their  exact 
signification. 

The  use  of  new  words  should  be  avoided,  when  there 
is  no  urgent  occasion  for  them,  since  their  introduction, 
in  such  cases,  only  clogs  a  language,  like  useless  wheels 
in  a  machine.  It  also  fosters  error,  owing  to  the  com- 
mon tendency  to  assume  that  different  words  must  de- 
note different  things.  Many  new  terms  have  sprung 
from  pedantry,  ignorance,  or  an  affectation  of  originality, 
superior  discernment,  and  refined  feelings,  which  had  no 
real  existence. 

§  3.  IMPERFECTIONS  AND  ABUSES  OF  LANGUAGE. — Origin  of  the  Im- 
perfections of  Language. — (1)  Idioms. — (2)  Different  admissible 
Constructions. — (3)  Different  Significations  of  Words. — (4)  Terms 
expressing  Nonentities. — (5)  Deficiency  of  Words. — (6)  Terms  con- 
veying false  Impressions. — (7)  Superfluous  Words. — Pernicious  Er- 
ror.— Requisite  in  order  to  a  right  understanding  of  Terms. — Ori- 
gin of  abuses  of  Language. — (1)  Using  vague  and  obscure  Words. 
— Common  Instance. — Sources  of  this  Abuse. — Means  of  guarding 
against  it. — (2)  Confounding  different  Significations. — How  to  be 
avoided. — (3)  Conveying  erroneous  Meanings. — Instances. — How- 
to  be  avoided. — Combination  of  Abuses. 

Language  represents,  not  the  realities  of  nature,  but 
the  opinions  of  those  who  formed  it ;  and  as  these  were 
often  erroneous,  language  exhibits  corresponding  imper- 
fections, of  which  the  following  are  the  principal : 


SEC.  3.]  ITS  IMPERFECTIONS.  195 

1 .  Language  abounds  with  idioms,  or  peculiar  phrases, 
the  precise  significations  of  which  are  not  indicated  by 
the  terms  composing  them,  but  must  be  learned  from  ob- 
serving the  occasions  on  which  they  are  used.     Conse- 
quently they  are  very  liable  to  be  misunderstood  by  those 
who  are  not  well  acquainted  with  the  language.    These, 
again,  may  mislead  others,  by  employing  or  defining 
those  terms  improperly. 

2.  Many  expressions  admit  of  various  constructions, 
every  one  of  which  gives  a  different  sense,  while  it  may 
be  difficult  to  ascertain  the  true  construction ;  and  con- 
sequently it  is  often  missed. 

3.  Owing  to  the  new  significations  superinduced  on 
the  primary,  many  icords  denote  things  widely  different, 
some  of  which  are  readily  mistaken  for  others,  because 
the  different  significations  are  often  connected  in  sense, 
and  always,  by  the  bond  of  the  common  name. 

4.  Many  expressions  denote  things  which  have  no  ex- 
istence.    Such  are  satyr,  dryad,  fairy,  mermaid,  sylph, 
griffin,  empyrean,  and  primum  mobile.     As  the  names 
exist,  we  are  apt  to  think  that  they  denote  correspond- 
ing realities,  which,  however,  are  wholly  imaginary. 

5.  No  word  exists  for  many  things  ichich  ought  to  be 
distinguished  by  a  peculiar  term.     Hence  it  becomes  nec- 
essary, either  to  affix  new  significations  to  old  words,  or 
to  introduce  new  terms,  in  order  to  denote  such  things ; 
and  this  produces  changes  which  render  language  either 
more  vague  or  less  intelligible. 

C.  Terms  have  been  invented  to  express  things  regard- 
ing which  vague  or  erroneous  opinions  prevailed  at  the 
time  of  their  formation,  so  that  they  convey  false  impres- 
sions regarding  the  reality.  Such  are  animal  spirits, 
humor,  sensible  species,  and  vitality.  Terms  of  this  kind 
had  no  clear  and  correct  signification  originally ;  and  sub- 
sequent alterations  sometimes  made  matters  still  worse. 

7.  Language  contains  many  icords  so  nearly  resem- 
bling each  other  in  signification  that  one  or  more  of  them 
might  be  discarded  to  advantage.  Such  are  perhaps,  per- 
adventure  and  perchance  —  among,  amongst,  amid  and 
amidst — nitrogen  and  azote  —  and  betiveen  and  betwixt. 
Not  only  are  slight  modifications  of  the  same  thing  oft- 
en denoted  by  totally  different  terms,  but  the  very  same 
thing  sometimes  has  several  names ;  and  hence  we  are 
apt  to  think  that  the  things  meant  must  be  as  distinct  as 


196  LANGUAGE.  [CHAP.  XL 

the  words  by  which  they  are  expressed.  Wherever  any 
of  these  modifications  do  not  require  to  be  frequently 
mentioned  in  discourse,  as  distinct  from  its  class,  the 
proper  plan  would  be,  to  denote  it  by  the  general  term, 
with  some  epithet  indicative  of  its  peculiarity,  and  to 
drop  the  special  term  altogether.  This  would  render  lan- 
guage more  intelligible,  precise,  and  easier  of  acquisition. 

To  overlook  the  preceding  imperfections,  and  assume 
that  language  gives  a  faithful  and  intelligible  represent- 
ation of  nature,  is  an  ancient  and  still  prevalent  error, 
which  has  produced  many  fallacies.  Some  believe  that 
there  are  fairies  because  we  have  a  name  for  them ;  and 
most  of  the  ancient  astronomers  never  suspected  that  their 
"crystalline  spheres"  were  wholly  imaginary.  Hence, 
also,  has  arisen  the  erroneous  opinion  that  a  knowledge 
of  nature  can  be  communicated  by  means  of  words  alone, 
whereas  we  cannot  be  instructed  by  words  which  we  do 
not  understand,  and  the  signification  of  a  term  can  never 
be  understood,  unless  we  learn,  by  our  own  original  com- 
prehension, the  primary  elements  of  the  thing  which  it 
denotes,  just  as  no  definition  can  give  the  blind  a  correct 
notion  of  color. 

Owing  to  the  fallible  nature  of  our  faculties,  and  their 
being  often  swayed  by  prejudices  or  bad  motives,  we 
are  liable  to  use  language  improperly,  even  if  it  were 
perfect,  while  these  abuses  are  increased  by  its  imperfec- 
tions. The  most  common  of  those  abuses  may  be  re- 
ferred to  one  or  other  of  the  following  heads : 

1.  Language  is  used  so  vaguely  or  obscurely  that  it  is 
very  difficult  to  ascertain  the  sense,  or  ichether  any  defi- 
nite sense  is  conveyed.  A  common  instance  of  this  abuse 
is,  where  figurative  expressions  are  employed,  so  that  we 
either  cannot  know  what  is  meant,  or  we  are  unable  to 
determine  whether  the  expression  is  figurative  or  literal. 
When  compositions  which  abound  with  this  defect  are 
carefully  analysed,  it  will  generally  be  found  that  the 
author  had  neither  a  clear  conception  of  his  own  mean- 
ing, nor  a  good  knowledge  of  his  subject. 

"This  abuse  is  of  common  occurrence,  and  frequently 
very  pernicious  in  its  consequences.  It  springs  ^chiefly 
from  ignorance,  carelessness,  an  affectation  of  originality, 
learning  or  depth,  and  dishonest  intentions. 

A  man  cannot  express  himself  clearly  and  accurately, 
in  his  own  words,  on  a  subject  which  he  does  not  under- 


SEC.  3.]  ITS  ABUSES.  197 

stand:  and  this  appears  to  be  the  source  of  much  of  the 
obscurity  and  darkness  which  characterizes  many  treat- 
ises and  compositions  on  mental  science;  for  the  lan- 
guage is  frequently  erroneous,  whichever  way  it  may  be 
interpreted.  But  as  the  subjects  of  investigation  are  im- 
perceptible to  the  senses,  these  faults  are  apt  to  escape 
the  reader  or  hearer's  attention ;  and  he  may  thus  admit 
as  self-evident  or  fairly  proved,  a  proposition  really  ab- 
surd, or  incapable  of  valid  proof. 

It  is  easy  to  assume  that  everything  is  correct,  where 
there  is  nothing  manifestly  false,  while  it  is  sometimes 
difficult  to  detect  the  true  character  of  profound  jargon 
or  sublime  twaddle ;  and  hence  these  have  often  passed 
for  being  what  they  appear.  It  requires  no  severe  think- 
ing to  employ  such  language,  while  it  procures  the  ad- 
miration of  those  who  believe  that  the  depth  of  a  dis- 
course must  be  proportional  to  its  darkness,  and  that 
what  they  readily  and  clearly  understand,  must  be  com- 
paratively superficial,  whereas  the  case  is  very  frequently 
the  exact  reverse.  This  leads  the  shallow-minded  and 
dishonest  to  use  foggy,  recondite  and  high-sounding  ex- 
pressions, when  clear  and  ordinary  terms  would  be  much 
more  appropriate. 

Carelessness  frequently  leads  to  similar  results.  If  a 
person  is  hurried,  and  inattentive  to  his  words,  he  will 
often  use  terms  which  convey  no  clear  or  definite  mean- 
ing to  the  party  addressed,  although  his  own  views  of 
the  subject  should  be  both  accurate  and  profound.  This 
is  particularly  apt  to  occur  where  he  has  paid  little  at- 
tention to  the  proper  expressions  for  denoting  his  mean- 
ing. 

A  common  temptation  to  indulge  in  this  kind  of  com- 
position is,  the  air  of  originality,  profundity,  and  import- 
ance, which  trite  or  puerile  thoughts  assume,  in  the  eyes 
of  many,  when  they  are  clothed  in  a  new,  vague,  and 
pompous  phraseology. 

Another  frequent  source  of  this  abuse  of  language  is,  a 
desire  to  mislead  those  addressed,  or  to  shun  the  respons- 
ibility of  telling  the  truth  clearly,  by  employing  obscure 
or  ambiguous  terms,  while  the  speaker  or  writer  escapes 
the  charge  of  unequivocal  lying,  because  his  expressions 
are  true  in  one  sense,  although  he  is  well  aware  that  they 
will  be  understood  otherwise,  or  at  least  produce  errone- 
ous impressions. 


198  LANGUAGE.  [CHAP.  XL 

Many  terms  denote  things  which  have  various  forms, 
or  are  incessantly  changing  their  import,  so  that  when 
used  without  any  qualifying  or  distinctive  epithets,  it 
may  be  impossible  to  ascertain  the  thing  meant.  Such 
are  wealth,  capital,  government,  legislature,  church,  and 
polity.  A  statement  which  holds  true  of  one  of  the 
things  denoted  by  such  terms,  may  be  quite  false  of  an- 
other. 

A  careful  attention  to  what  is  actually  said,  will  enable 
us  to  estimate  expressions  at  their  true  value,  and  pre- 
vent us  from  overvaluing  puerility  or  absurdity,  because 
they  may  be  clothed  in  a  novel  or  philosophic  garb ;  and 
we  shall  learn  that  vague,  obscure,  and  grandiloquent 
language  generally  covers  error  or  inanity. 

2.  The  same  expressions  are  employed  in  various  sig- 
nifications, which  are  not  distinguished,  so  that  we  mis- 
ta'ke  one  for  another.     The  author  uses  the  same  words 
now  in  one  sense,  and  then  in  another,  while  he  gives  no 
clear  indication  of  the  difference :  but  we  are  required, 
or  at  least  expected,  to  assume  that  they  are  used  in  the 
same  sense  throughout.    This  abuse  is  of  frequent  occur- 
rence, because  it  is  very  liable  to  escape  the  notice  of 
both  author  and  hearer  or  reader.    We  are  so  accustom- 
ed to  use  the  same  word  in  different  senses,  that  the  fact 
of  this  being  done  excites  neither  surprise  nor  suspicion; 
and  hence  we  are  very  apt  to  overlook  the  abuse  of  do- 
ing so,  while  the  argument,  or  object  in  hand,  requires 
that  they  should  be  employed  throughout  in  precisely 
the  same  sense. 

To  guard  against  this  abuse,  we  must  ascertain  wheth- 
er the  expressions,  while  professing  to  mean  only  one 
thing,  are  not,  in  reality,  employed  to  denote  several 
things  essentially  different.  This  is  done  by  ascertain- 
ing the  precise  sense  in  wrhich  the  terms  are  employed, 
wherever  they  occur.  In  our  own  case,  we  must  closely 
question  ourselves  regarding  our  meaning,  ascertain 
whether  we  know  the  precise  thing  that  we  intend  to 
express,  and  adhere  to  the  rules  of  proper  expression. 
In  the  case  of  others,  we  must  also  apply  the  proper 
rules  of  interpretation. 

3.  Language  is  employed  which  conveys  a  clear  and 
definite,  but  erroneous,  signification :  and  this  may  be  done 
unconsciously,  through  ignorance   and  heedlessness,  or 
wilfully,  from  some  evil  design.     A  common  form  of  this 


SEC.  3.]  ITS  ABUSES.  "l99 

abuse  is,  to  employ  one  term  for  another  which  it  some- 
what resembles  in  sense,  while  their  proper  significations 
are  very  different.  Thus  the  words  impossible,  incon- 
ceivable, incomprehensible,  and  highly  improbable,  which 
properly  denote  four  things  essentially  different,  have  oft- 
en been  employed  indiscriminately,  as  if  they  all  express- 
ed the  same  thing. 

Another  common  modification  of  this  abuse  is,  errone- 
ous definition.  Thus,  several  of  our  older  English  lexi- 
cographers tell  us  that  the  share  or  sock  of  a  plough  is 
the  coulter  or  knife,  which  is  like  saying  that  the  hand  is 
the  foot.  So  the  Hebrew,  Greek  and  Latin  term  for  cop- 
per is  generally  defined,  in  the  dictionaries  of  these  lan- 
guages, by  brass,  an  alloy  which  appears  to  have  been 
wholly  unknown  to  the  ancients.  This  error  is  very  apt 
to  escape  detection,  because  those  who  consult  the  defi- 
nition are  generally  ignorant  of  the  real  import  of  the 
word.  We  should  never  rely  on  the  definitions  of  per- 
sons who  are  not  well  informed  regarding  the  thing  de- 
fined, but  either  apply  to  a  proper  authority,  or  endeavor 
to  acquire  some  knowledge  of  the  thing  defined,  and 
then  compare  the  reality  with  the  definition. 

A  third  common  case  of  this  abuse  is,  exaggeration 
and  extenuation.  On  the  one  hand  grandiloquent  or  hy- 
perbolical language  is  applied  to  things  which  do  not 
properly  admit  of  it :  and  on  the  other  hand,  terms  ex- 
pressive of  contempt  are  either  overstrained  or  wholly 
misapplied.  This  course  sometimes  produces  the  desired 
effect,  especially  where  it  tallies  with  the  prejudices  of 
the  party  addressed.  In  other  cases,  the  result  is  often 
the  very  reverse.  Instead  of  being  elevated,  the  lan- 
guage is  only  tumid  or  bombastic,  in  the  one  case :  and 
compassion  for  its  objects,  with  indignation  against  those 
who  employ  it,  are  the  effects  in  the  other. 

This  abuse  is  to  be  detected  by  ascertaining  the  char- 
acter and  circumstances  of  the  author,  and  applying  the 
proper  criterions  of  testimony. 

Not  unfrequently  two  or  three  of  the  preceding  abuses 
are  combined,  as  where  vague  terms  are  employed  to 
convey  an  erroneous  meaning,  while  the  same  terms  are 
improperly  used  in  various  senses.  Here  we  should  first 
try  to  ascertain  what  is  said,  and,  if  we  succeed  in  this, 
endeavor  to  learn  its  character  afterwards.  If  we  fail  in 
the  former  object,  the  second,  of  course,  becomes  imprac- 
ticable. 


200 '  LANGUAGE.  [CHAP.  XI. 

§  4.  INTERPRETATION  OF  LANGUAGE. — Use  and  foundation  of  Rules 
of  Interpretation. — -Five  classes  of  Expressions. — Three  which  re- 
quire interpretation. — (1)  Usual  Meanings  to  be  generally  adopted. 
— On  what  this  rule  is  based. — Principal  Exceptions. — On  what 
ground  these  are  admitted. — (2)  When  Figurative  Meanings  are  to 
ba  adopted. — Mode  of  determining  when  an  expression  is  figura- 
tive.— (3)  When  special  or  technical  senses  are  to  be  adopted. — Re- 
lations and  places  of  the  Figurative  and  the  Technical. — Means  of 
discovering  the  latter. — (4)  Rule  regarding  antiquated  Significa- 
tions.— How  these  are  to  be  ascertained. — (5)  Rule  regarding  the 
intentional  Sense. —  Its  Application. —  Means  of  ascertaining  this 
Sense. — (6)  Cases  in  which  the  literal  Signification  must  be  adopt- 
ed, and  why. —  (7)  Usages  to  be  observed. — Foundations  of  this 
Rule. — Means  of  ascertaining  Usages. — Interpretation  of  Idioms. — 
Observations  on  Corresponding  Terms,  and  those  which  gradually 
change  their  Significations. — Applications  of  the  Rule. — Various 
things  to  be  considered. —  Caution. —  Mannerism. —  Influence  of 
particular  Pursuits  and  national  Character. — (8)  Rule  where  sev- 
eral meanings  are  admissible.  —  Its  Foundations  and  Extent.  — 
Means  of  application. — Common  violation  of  it. — How  to  be  avoid- 
ed.— Remarks  on  cases  to  which  it  is  inapplicable. — Latent  Am- 
biguities.— Implications. — Aids  where  we  depend  on  Translations. 
— Requisites  to  a  proper  application  of  the  Rules  of  Interpretation. 
— Sources  and  Evils  of  Misinterpretation. 

The  difficulties  which  arise,  in  attempting  to  ascertain 
the  precise  meaning  of  expressions,  are  to  be  surmount- 
ed by  a  proper  application  of  the  rules  of  interpretation. 
These  are  founded  on  the  structure  and  usages  of  lan- 
guage, so  that  their  validity  admits  of  no  question,  al- 
though people  may  differ  occasionally  regarding  their 
applications. 

With  reference  to  interpretation,  all  expressions  may 
be  divided  into  the  five  following  classes.  (16) 

1.  Those  of  ichich  the  signification  is  well  known, 
clear,  unchangeable  and  unambiguous.     This  class  in- 
cludes most  of  the  names  of  natural  objects,  and  those 
words  which  denote  simple  external  actions  and  direct 
comprehensions,  such  as  Sun,  Moon,  sky,  tree,  man,  hand, 
foot,  black,  white,  hot,  cold,  go,  come,  sit,  eat,  drink,  see, 
hear,  &c.    To  all  who  possess  an  ordinary  knowledge  of 
the  language,  words  of  this  kind  require  no  interpreta- 
tion ;  and  it  is  chiefly  by  their  aid  that  we  can  rightly 
interpret  others. 

2.  Those  which  convey  no  real  meaning.     Here  inter- 
pretation is  needless,  as  it  would  be  folly  to  search  for  a 
meaning  where  none  exists. 

3.  Those  which  are  ambiguous,  or  which  admit  of  sev- 
eral interpretations. 


SEC.  4.]  INTERPRETATION.  201 

4.  Those  which  are  obscure,  or  in  which  we  cannot 
readily  discover  any  certain  meaning. 

5.  Those  of  which  the  meaning  is  wholly  unknown, 
such  as  obsolete  and  unusual  words,  and  foreign  terms 
of  which  we  have  not  yet,  in  any  degree,  ascertained  the 
significations. 

Thus  we  see  that  the  ambiguous,  the  obscure,  and  the 
unknown  comprise  the  whole  field  of  interpretation :  and 
the  following  are  the  principal  rules  for  removing  the 
difficulties  which  they  occasion  : 

1.  The  literal  or  ordinary  signification  of  words  is  al- 
ways to  be  adopted,  except  where  there  is  some  urgent  rea- 
son for  departing  from  it.     This  rule  is  founded  on  the 
fact  that  the  literal  is  the  common  or  usual  signification, 
to  which  all  others  are  only  exceptions. 

The  following  are  the  principal  cases  in  which  we 
ought  to  depart  from  the  literal  signification  :  (1)  Where 
it  renders  the  expression  absurd,  or  gives  it  a  meaning 
which  cannot  possibly  be  true.  (2)  Where  it  gives  either 
a  puerility  or  no  meaning  at  all.  (3)  Where  it  gives  the 
passage  a  meaning  at  variance  with  known  truth,  the 
whole  scope  and  tenor  of  the  discourse,  or  the  mews  and 
opinions  of  the  author. 

These  exceptions  to  the  general  rule  are  admitted  on 
the  grounds  that  figurative  and  special  meanings  of  words 
are  common,  that  persons  do  not  generally  speak  mani- 
fest absurdities  and  puerilities,  that  their  expressions  usu- 
ally have  a  meaning,  that  they  sometimes  employ  words 
which  convey  a  sense  different  from  what  they  intended, 
and  that  they  seldom  utter  glaring  falsehoods,  or  direct- 
ly contradict  themselves. 

In  all  those  exceptional  cases,  we  must  search  for  some 
other  sense  than  the  literal ;  and  of  this,  kind  the  figura- 
tive, the  special  or  technical,  the  antiquated  and  the  in- 
tentional, are  the  most  common. 

2.  A  figurative  rendering  is  to  be  adopted  ichere  it  is 
admissible,  and  gives  a  good  sense,  which  the  literal  does 
not  give.     The  various  kinds  of  figures,  and  the  circum- 
stances under  which  they  are  employed,  are   so  well 
known  that  it  is  generally  easy  to  determine  when  a  fig- 
urative meaning  is  to  be  adopted :  and  we  are  farther 
aided  by  the  manifest  difficulties  attending  a  literal  in- 
terpretation, in  such  cases. 

The  nature  of  the  composition  often  indicates  whether 
12 


202  LANGUAGE.  [CHAP.  XL 

an  expression  is  figurative!  In  poetry,  rhetorical  com- 
positions, and  all  impassioned  discourse,  figurative  lan- 
guage abounds,  while  it  is  sparingly  used  in  all  scientific 
works,  and  in  some  it  is  hardly  ever  employed.  As  the 
oldest  compositions  mostly  belong  to  the  former  class, 
they  generally  exhibit  a  free  use  of  figurative  language ; 
and  they  are  to  be  interpreted  accordingly. 

Those  expressions  which  were  originally  figurative,  but 
have  entirely  lost  their  old  literal  signification,  are  ex- 
cepted  from  the  preceding  observation  ;  for  as  the  figura- 
tive has  become  the  ordinary  signification,  they  are  prop- 
erly classed  with  literal  expressions. 

3.  The  special  or  technical  signification  is  to  be  adopt- 
ed where  it  is  indicated  by  the  subject  or  the  context,  and 
the  ordinary  signification  is  objectionable.     By  the  for- 
mer terms  is  understood  that  signification  which  is  pecul- 
iar to  a  certain  art  or  science,  or  is  employed  only  by  a 
particular  class  of  persons,  in  speaking  of  their  distinctive 
usages,  opinions,  or  doctrines. 

Figurative  and  special  expressions  are  generally  in  in- 
verse proportion.  The  latter  are  extensively  employed 
in  purely  didactic  works,  and  very  little  in  impassioned 
or  emotional  discourse.  In  the  former,  the  special  signi- 
fication is  the  rule,  and  the  ordinary,  the  exception,  so 
far  as  the  subject  in  hand  is  concerned. 

The  subject  of  discourse  generally  indicates  the  partic- 
ular meaning  which  we  are  to  expect.  A  sailor  general- 
ly uses  terms  in  their  nautical,  a  soldier,  in  their  milita- 
ry, a  merchant,  in  their  commercial,  and  a  geometrician, 
in  their  mathematical  signification. 

The  signification  of  the  various  terms  is  to  be  discov- 
ered from  the  oral  or  written  testimonies  of  those  con- 
versant with  the  subject  to  which  they  refer,  or  from 
marking  their  usages  and  formal  definitions ;  and  much 
aid  may  be  derived  from  good  dictionaries  of  the  partic- 
ular subject,  where  such  exist. 

4.  Antiquated  significations  are  to  be  adopted  in  an- 
cient compositions,  or  such  as  treat  of  Antiquities.    The 
general  subject,  or  the  context,  points  out  the  cases  in 
which  antiquated  meanings  are  admissible ;  and  the  prin- 
cipal thing  to  be  avoided  is,  confounding  the  obsolete 
with  the  present  meaning.     The  former  may  be  ascer- 
tained from  dictionaries  which  explain  them,  archaBolog- 
ical  treatises,  and  an  extensive  acquaintance  with  works 


SEC.  4.]  INTERPRETATION.  203 

on  the  subject  in  question,  written  in  the  same  age  and 
country. 

5.  The  sense  intended  to  be  conveyed  is  to  be  adopted, 
though  different  from  what  the  words  ordinarily  signify. 
Speakers  or  writers  sometimes  inadvertently  omit  or  in- 
sert words,  or  employ  expressions  which  convey  a  sense 
quite  different  from  what  they  intended,  in  all  of  which 
cases  the  latter  is  evidently  the  true  interpretation. 

In  determining  the  applicability  of  this  rule,  the  cir- 
cumstances of  the  author  are  to  be  considered.  If  he 
Avrote  or  spoke  deliberately,  and  after  careful  considera- 
tion, the  rule  is  not  applicable,  unless  the  intentional 
meaning  is  obvious  and  unquestionable,  and  certainly 
different  from  the  literal.  In  other  cases,  this  rule  may 
safely  be  followed,  wherever  the  words  actually  employ- 
ed are  such  as  might  readily  be  used  inadvertently,  in- 
stead of  those  which  would  properly  express  the  mean- 
ing supposed  to  be  intended,  while  this  harmonizes  with 
the  context,  and  the  literal  signification  either  contradicts 
it,  or  gives  no  sense  at  all,  as  when  the  negative  particle, 
or  the  verb,  is  omitted.  But  the  rule  cannot  safely  be 
applied,  where  the  supposed  intended  sense,  though  prob- 
able, cannot  be  clearly  ascertained. 

Wherever  the  intentional  sense  differs  from  the  literal, 
it  is  generally  to  be  ascertained  from  the  context,  or  the 
author's  other  statements ;  and,  not  unfrequently,  it  is 
discovered  from  his  acts,  demeanor  or  circumstances. 

6.  N~o  meaning  is  to  be  attached  to  an  expression, 
which  it  will  not  bear :  and  the  ordinary  signification  is 
alivays  to  be  adopted,  where  no  other  is  admissible.    The 
rules  of  interpretation  assume  that  the  meaning  which  is 
to  be  attached  to  an  expression,  is  one  which  it  may  pos- 
sibly convey,  and  which  is  not  wholly  inconsistent  with 
the  usages  of  speech  :  for  it  is  evidently  absurd  to  attach 
any  such  meaning  to  words ;  and,  therefore,  we  are  al- 
ways limited  to  admissible  senses,  whatever  be  the  con- 
sequences. 

7.  Expressions  are  to  be  interpreted  according  to  the 
usages  of  the  language,  the  age,  the  place,  the  subject,  and 
the  author.     This  rule  is  based  on  the  well-known  fact 
that  these  usages  widely  differ.    Every  language  abounds 
with  idioms,  or  expressions  which  have  a  conventional 
meaning,  well  understood  by  those  who  are  familiar  with 
it,  but  frequently  very  obscure  to  all  others  :  and  a  simi- 


204  LANGUAGE.  [CHAP.  XI. 

lar  remark  applies  to  different  ages,  places,  subjects  and 
authors. 

Usage  is  learned  from  passages  or  expressions  where 
circumstances  render  the  exact  meaning  obvious,  as  when 
we  observe  the  occasions  on  which  the  expression  "  How 
do  you  do  ?"  is  used.  The  meaning  then  becomes  clear, 
whereas  it  is  quite  a  mystery  to  a  person  who  observes 
it  for  the  first  time  in  a  book.  In  many  cases,  the  sense 
is  fixed  by  the  immediate  context,  as  if  we  notice  the 
answer — "  I  am  quite  well,"  given  to  the  preceding  ques- 
tion :  and  when  the  usage  is  thus  ascertained,  it  may  be 
applied  to  remove  the  various  difficulties  which  it  occa- 
sions. 

The  usages  of  a  particular  author  are  best  ascertained 
from  his  own  works,  although  they  are  frequently  point- 
ed out  in  grammars  and  dictionaries :  but  much  assist- 
ance may  be  derived  from  an  acquaintance  with  his  bi- 
ography, and  the  circumstances  in  which  he  was  placed, 
as  well  as  the  history  of  his  age  and  country. 

The  peculiar  usages  of  various  countries  and  ages  are 
best  learned  from  their  respective  authors ;  and  many 
of  them  are  pointed  out  in  grammatical  and  archaeolog- 
ical works.  But  many  are  best  learned  from  a  good 
knowledge  of  the  nation's  public  and  private  life  and  man- 
ners. The  corresponding  terms  for  artificial  objects  dif- 
fer, of  course,  as  much  as  the  objects  themselves.  Thus, 
the  words  writing,  auger,  plough,  coat,  &c.,  have  differ- 
ent shades  of  meaning,  in  different  ages  and  countries. 
The  corresponding  words  expressive  of  mental  objects 
sometimes  differ  still  more  widely.  Thus,  among  the  an- 
cient Romans,  pious  meant  dutiful  or  well-behaved,  and 
religion  denoted  only  the  rites  and  ceremonies  pertain- 
ing to  the  worship  of  the  gods. 

Many  words  change  their  significations  gradually,  from 
age  to  age ;  and,  therefore,  the  age,  as  well  as  the  coun- 
try, of  the  author  must  be  noted,  although  the  language 
may  not  have  undergone  any  radical  change.  The  sig- 
nifications of  many  words  used  by  English  authors  of  the 
fourteenth  century,  for  example,  differ  widely  from  those 
which  they  bear  at  the  present  day. 

In  some  cases  we  must  consider,  not  only  the  age  and 
country,  but  also  the  dialect,  or  local  usage :  and  here  we 
must  interpret  the  expressions  according  to  the  peculiar 
dialect  of  their  author. 


SEC.  4.]  INTERPRETATION.  205 

The  subject  of  discourse,  also,  requires  attention :  for 
many  terms  have,  not  only  a  general  and  a  technical 
meaning,  but  several  kinds  of  each ;  and  the  subject  is 
frequently  an  important  guide  in  determining  which  of 
these  ought  to  be  adopted.  We  should  generally  attrib- 
ute to  such  words  the  peculiar  sense  which  they  usually 
bear,  in  the  subject  in  which  they  occur,  or  among  the 
class  to  which  the  author  belongs. 

The  character,  circumstances,  objects,  and  pursuits,  of 
an  author,  are  often  of  great  importance  in  determining 
the  sense  of  his  expressions.  It  is  also  necessary  to  note 
his  general  style.  Some  follow  common  usage  so  closely 
that  their  compositions  present  no  peculiarities  which 
can  cause  any  difficulties  of  interpretation,  while  others 
follow  an  opposite  course.  The  former  are  generally  su- 
perior, in  every  important  respect.  Men  of  an  original 
cast  of  mind  frequently  exhibit  marked  peculiarities  of 
style  :  but  the  highest  order  of  minds  is  characterized  by 
the  clearness  and  precision,  as  well  as  the  force  of  their 
style. 

A  knowledge  of  individual  peculiarities  is  occasionally 
of  more  consequence  than  that  of  an  author's  age,  since 
some  affect  the  style  of  former  generations,  while  others 
study  novelty  of  expression.  But  this  has  generally 
been  done  by  inferior  authors,  who  attempted  to  excite 
by  their  manner  a  degree  of  attention  which  could  not 
be  secured  by  their  matter. 

Individual  peculiarities  often  affect  language,  by  lead- 
ing to  the  employment  of  terms  in  a  technical  sense, 
when  they  should  be  used  in  their  more  general  signifi- 
cation ;  and  persons  often  err  in  using  the  technical 
terms  with  which  they  are  familiar,  instead  of  the  appro- 
priate expressions.  An  old  seaman's  dialect  generally 
shows  many  instances  of  this  kind.  Here  we  should 
look  to  the  usage  of  the  class  to  which  the  individual 
belongs,  for  an  explanation  of  his  meaning.  Thus,  ambi- 
guities in  contracts  are  often  removed  by  referring  to  the 
usages  of  the  trade  or  vocation  to  which  they  refer.  Dif- 
ficulties of  this  kind  are  sometimes  surmounted  by  ob- 
serving the  conduct  of  the  party,  either  when  he  em- 
ployed the  expressions  or  at  some  other  time,  just  as  we 
learn  the  signification  of  terms  wholly  unknown,  by  ob- 
serving their  applications. 

The  character  of  an  author's  nation  ought  not  gener- 


206  LANGUAGE.  [CHAP.  XI. 

ally  to  be  overlooked,  in  interpreting  his  language,  as  it 
frequently,  to  a  great  extent,  controls  individual  peculiar- 
ities. Nations  of  ardent  dispositions  and  undisciplined 
intellects  are  apt  to  use  language  stronger  than  truth 
warrants,  while  that  of  men  of  cooler  dispositions  and 
more  discriminating  judgements  are  to  be  taken  much 
more  literally.  The  lofty  terms  of  the  former  often  mean 
much  less  than  the  more  sober  expressions  of  the  latter. 

8.  "Where  several  meanings  are  admissible,  we  should 
generally  adopt  that  which  best  harmonizes  with  the  con- 
text, the  author's  circumstances,  views,  and  objects,  and  the 
character  of  those  whom  he  addresses.  This  rule  is  based 
on  the  assumptions  that  one  part  of  a  composition  gener- 
ally harmonizes  with  another,  that  an  author  will  employ 
words  in  the  sense  best  adapted  to  promote  his  objects, 
that  his  expressions  have  a  meaning,  and  only  one  real 
meaning,  and  that  he  will  endeavor  to  render  himself  in- 
telligible to  those  whom  he  addresses.  These  assump- 
tions generally  hold  true  of  the  language  of  sensible  men, 
who  speak  or  write  with  proper  objects  in  view,  and  on 
a  subject  which  they  understand.  But  when  the  author 
is  a  simpleton,  or  when  he  composes  with  other  objects 
than  to  instruct,  or  deal  fairly  with  those  whom  he  ad- 
dresses, this  rule  does  not  apply. 

The  proper  application  of  this  rule  requires  some 
knowledge  of  the  general  nature  of  the  subject,  the  au- 
thor's particular  character  and  objects,  and  also  the  char- 
acter of  those  whom  he  addresses.  These  may  be  learn- 
ed partly  from  the  general  tenor  of  the  language,  and 
partly  from  other  sources,  such  as  the  testimonies  of  con- 
temporaries, acquaintances,  or  persons  similarly  circum- 
stanced. 

In  the  case  of  spoken  discourse,  the  application  of  this 
rule  is  facilitated  by  observing  the  speaker's  gestures, 
looks,  and  tones  of  voice.  We  are  thus  enabled,  in  many 
cases,  to  distinguish  irony  and  other  figures  from  literal 
speech,  and  to  ascertain  the  force  and  purport  of  the  lan- 
guage, without  any  difficulty.  In  written  discourse,  no 
such  aid  is  generally  available :  but  we  may  often  ascer- 
tain the  true  meaning  by  referring  to  analogous  expres- 
sions, or  to  the  author's  direct  explanation  of  the  same 
subject  or  the  passage  in  question. 

A  frequent  violation  of  this  rule  is,  to  interpret  an  ob- 
scure or  ambiguous  passage  so  as  to  make  it  clash  with 


SEC.  4.]  INTERPRETATION.  207 

others  which  admit  of  only  one  interpretation,  and  then 
to  force  a  meaning  on  the  latter  of  which  they  do  not  ad- 
mit, in  order  to  make  them  harmonize  with  the  false  sig- 
nification previously  attached  to  the  former  passage.  It 
is  evidently  absurd  to  force  what  is  clear  into  conformi- 
ty with  the  supposed  signification  of  what  is  dark.  The 
proper  course  is,  to  attach  to  words  no  signification 
which  they  will  not  fairly  bear,  and  to  interpret  what  is 
obscure  or  ambiguous  so  as  to  make  it  tally  with  what 
is  free  from  any  such  difficulty,  and  rightly  admits  of 
only  one  meaning. 

This  rule  is  frequently  inapplicable  to  the  joint  compo- 
sition of  different  persons,  who  entertained  conflicting 
views  of  the  subject,  such  as  state  papers,  laws,  treaties, 
and  contracts.  As  these  often  speak  the  language  and 
opinions  of  different  authors,  in  their  various  parts,  they 
may  be  quite  inconsistent  with  each  other,  while  we  may 
have  no  means  of  knowing  the  author  of  any  particular 
part.  The  same  remarks  apply  to  the  different  compo- 
sitions of  a  person  who  has  changed  his  views  in  the  in- 
terval, or  who,  at  one  time,  expresses  his  own  opinion, 
and  at  another  time,  those  of  other  parties,  whom  he 
wishes  to  please. 

Sometimes  the  same  part  of  a  joint  composition  has 
different  meanings,  because  its  authors  understood  it  dif- 
ferently, or  pretend  that  they  did  so,  as  in  many  cases 
of  contracts. 

With  regard  to  all  joint  compositions,  the  safest  course 
generally  is,  to  adhere  to  the  sense  given  by  the  other 
rules  of  interpretation,  exclusive  of  the  present,  and,  if 
these  do  not  give  a  definite  signification,  to  attach  to  the 
language  no  precise  meaning  whatever. 

Sometimes  expressions  apparently  very  precise,  are,  in 
reality,  ambiguous,  owing  to  extrinsic  circumstances,  as 
where  a  man  wills  his  large  English  Bible  to  his  son  John, 
and  it  turns  out  that  he  left  two  such  Bibles.  Here  we 
should  first  ascertain,  from  extrinsic  evidence,  the  facts 
affecting  the  sense,  and  then  apply  the  ordinary  rules  of 
interpretation. 

A  frequent  source  of  difficulty  is,  the  uncertainty  which 
exists  as  to  what  may  be  implied  in  the  expressions :  for 
we  are  left  to  infer  the  author's  meaning  from  words 
which,  of  themselves,  may  convey  no  precise  or  unequiv- 
ocal signification.  The  author's  character,  object,  and 


208  LANGUAGE.  [CHAP.  XI. 

circumstances,  and  the  context  of  the  discourse,  are  the 
principal  guides  for  removing  such  difficulties ;  and  where 
these  fail  to  do  so,  the  only  safe  course  generally  is,  to 
let  the  expressions  go  for  nothing. 

Even  where  an  inference  may  be  necessarily  deducible 
from  a  person's  language,  we  are  not  always  warranted 
in  assuming  that  he  intended  to  convey  it :  for  he  may 
either  have  overlooked  it,  or  not  discerned  the  necessary 
connection.  We  may  generally  infer  that  a  person  im- 
plies what  one  of  his  character  and  in  his  circumstances 
naturally  would,  but  it  is  only  where  his  character,  or 
the  immediate  and  palpable  nature  of  the  inferences  ex- 
cludes other  suppositions,  that  we  can  safely  assume  he 
meant  to  express  the  inferences,  unless  we  have  some 
extraneous  proof  that  such  is  the  case. 

Where  we  are  obliged  to  rely  on  translations,  we  must 
look  carefully  to  the  context,  and  to  similar  or  corre- 
sponding passages,  either  in  the  same  or  in  other  authors, 
wherever  we  encounter  a  serious  difficulty;  and  much 
aid  may  be  derived,  in  all  such  cases,  from  comparing  in- 
dependent translations  of  the  same  passage. 

The  proper  application  of  the  rules  of  interpretation 
requires  freedom  from  the  influence  of  prejudice,  and,  in 
many  instances,  extensive  and  careful  research  and  con- 
sideration. Hence  misinterpretation  has  been  a  thing  of 
very  frequent  occurrence,  and  a  prolific  source  of  perni- 
cious errors.  The  interpreter  strongly  wished  that  a 
certain  interpretation  should  be  true,  and  consequently 
he  adopted  it ;  or  he  wished  that  the  true  meaning  should 
be  false ;  and  therefore  he  rejected  it. 

There  is  a  general  prejudice  in  favor  of  interpreting 
the  language  of  every  one  of  whom  we  think  favorably, 
so  as  to  make  it  harmonize  with  our  own  views  of  what 
is  true,  right,  or  expedient.  It  is  peculiarly  apt  to  mis- 
lead us  where  we  are  not,  in  reality,  wrell  acquainted 
with  the  subject,  and  yet  are  "hot  fully  aware  of  the  ex- 
tent of  our  ignorance.  We  should  remember  that  what 
we  think  or  would  have  done,  is  no  criterion  of  what 
others  thought  or  did. 


SEC.  1.]  SIGNS.  209 


CHAPTER  XII. 

OF   EVIDENCE. 

§  1.  GENERAL  PRINCIPLES  OP  EVIDENCE. — Two  kinds  of  Signs. — 
Conclusive  Signs. — How  ascertainable. — Three  classes  of  Probable 
Signs.— Mode  of  determining  the  value  of  a  Sign. — On  what  the 
general  credibility  of  Testimony  is  based. — Influence  of  Witness's 
moral  Character. — Means  of  determining  the  combined  force  of 
several  independent  Evidences. — Circumstantial  Evidence. — When 
satisfactory,  and  when  not. — Criterion. — Principles  of  its  Applica- 
tion.— Defects  of  Circumstantial  Evidence. — Means  of  determining 
the  degree  of  Probability. — Caution. 

Signs  are  either  conclusive,  or  only  probable,  evidence. 
They  are  conclusive  when  they  are  known,  by  induction 
or  any  other  means,  to  be  incompatible  with  the  falsity 
of  the  proposition  in  question,  or  to  be  uniformly  con- 
nected with  it,  and  never  to  accompany  any  other  state 
of  things,  except  in  some  peculiar  circumstances,  which 
are  absent  in  the  case  under  consideration.  Thus,  the 
appearance  of  frost  proves  that  the  weather  has  been 
cold,  and  the  mercury  standing  very  high  in  the  ther- 
mometer is  a  sure  sign  that  it  is  warm. 

The  usual  modes  in  which  a  phenomenon  is  shown  to 
be  a  conclusive  sign  of  something,  is,  by  proving  that 
they  are  connected  as  cause  and  effect,  or  that  they  are 
both  effects  of  a  known  cause,  or  that  they  are  connected 
as  premise  and  conclusion. 

Signs  are  only  probable  evidence  in  the  three  follow- 
ing cases. 

1.  Where  they  are  only  generally,  and  not  uniformly, 
connected  with  the  thing  in  question.     The  appearance 
of  swallows  is  only  a  probable  sign  that  spring  has  come, 
since  they  sometimes  appear  before  that  season  ;  and  the 
mercury  standing  very  high  in  the  barometer  is  only  a 
probable  indication  of  fair  weather,  since  that  phenome- 
non is  sometimes  speedily  followed  by  a  storm. 

2.  Where  they  are  sometimes  connected  with  other 
things  also.     A  person's  ceasing  to  breathe  is  only  a 
probable  sign  of  death,  since  that  sometimes  happens  to 
one  who  is  still  alive. 


210  EVIDENCE.  [CHAP.  XII. 

3.  'Where  they  are  merely  known  to  have  accompanied 
it,  in  all  the  cases  observed,  but  there  is  no  proof  that  they 
will  do  so  hereafter.  The  appearance  of  comets,  in  an- 
cient times,  was  followed  by  calamities;  and  hence  it 
was  inferred  that  they  portended  the  latter, — whereas 
we  now  know  that  they  have  not  the  least  connection 
with  each  other. 

In  judging  of  the  value  of  a  particular  sign,  as  an  evi- 
dence of  the  proposition  under  consideration,  we  should 
first  ascertain  its  real  character,  and  then  attach  to  it  the 
precise  degree  of  weight  which  that  warrants:  other- 
wise we  are  very  liable  to  be  misled  by  prejudices  and 
preconceived  opinions. 

The  general  credibility  of  testimony  is  based  on  the  two 
following  facts.  1.  It  requires  an  effort,  for  which  some 
motive  must  exist,  to  invent  a  falsehood,  or  to  conceive 
things  differently  from  what  actually  occurred :  for  this 
is  what  naturally  presents  itself  to  our  Memory  or  Ap- 
prehension. 2.  The  remembrance  of  a  lie  is  always  more 
or  less  painful,  since  we  sympathize  with  the  party  de- 
ceived, and  disrelish  the  thought  that  the  falsehood  may 
be  detected,  and  possibly  punished,  either  directly,  or  by 
loss  of  character  for  veracity,  and  withdrawing  future 
confidence. 

These  principles  operate  even  on  the  most  immoral 
and  unfeeling.  Hence  people  will  never  lie,  unless  they 
have  some  object  to  effect  by  doing  so  ;  and,  when  there 
can  be  no  such  object,  they  will  testify  truly.  The  ob- 
jects that  will  induce  a  person  to  lie,  depend  on  his  char- 
acter. Some  lie  habitually,  for  very  trifling  objects, 
while  others  adhere  to  truth  amidst  the  strongest  tempt- 
ations to  the  contrary.  The  latter  are  guided  by  cer- 
tain moral  principles,  or  fixed  rules  of  conduct,  which 
render  their  testimony  faithful,  under  circumstances 
which  would  lead  the  former  to  falsify  egregiously. 

In  many  cases,  there  are  various  evidences,  which  all 
go  to  prove  the  same  conclusion ;  but  every  one  of  them, 
taken  separately,  affords  only  a  probability  of  its  truth. 
Here  we  should  consider  whether  the  falsity  of  the  con- 
clusion is  compatible  with  all  the  evidences,  taken  to- 
gether. If  so,  there  is  only  a  probability  that  the  con- 
clusion is  true.  But  if  the  reliable  evidences  are  so  nu- 
merous as  to  exclude  the  supposition  of  their  being  all 
fortuitous  coincidences,  the  conclusion  is  established. 


SEC.  1.]  CIRCUMSTANTIAL  EVIDENCE.  211 

Circumstantial  evidence  consists  of  signs  or  testimo- 
nies from  which  the  proposition  in  question  may  possi- 
bly be  legitimately  inferred,  but  which  do  not  directly 
prove  it.  It  is  sometimes  more  satisfactory  than  direct 
testimony,  as  being  less  liable  to  mislead  us  from  the 
negligence  or  fraud  of  witnesses.  It  is  frequently  easy 
to  state  a  simple  direct  falsehood  which,  if  true,  would 
decide  the  question,  while  it  may  be  difficult  to  show  the 
falsity  of  the  statement,  owing  to  its  simplicity  and  con- 
ciseness ;  but  it  is  extremely  difficult  to  invent  a  series 
of  circumstantial  proofs  the  character  of  which  cannot 
be  easily  detected  by  a  careful  examination  of  them,  and 
comparing  them  with  known  truths. 

This  kind  of  evidence  is  always  unsatisfactory  where 
the  circumstances  are  not  so  numerous  and  direct  as  to 
exclude  the  supposition  of  fortuitous  connection,  or 
where  one  circumstance  disproves  the  conclusion  drawn 
from  another.  The  criterion  of  conclusiveness  is,  that 
when  all  the  facts  proved  are  certainly  incompatible  with 
any  supposition  but  one,  it  is  proved  to  be  true.  In  all 
other  cases,  circumstantial  evidence  can  prove  nothing 
more  than  a  probability. 

Whether  the  circumstances  of  a  particular  case  con- 
form to  the  criterion  or  not,  can  be  decided  by  no  gen- 
eral rule,  but  only  by  testing  them  by  the  proper  princi- 
ples, and  then  fairly  weighing  the  whole.  If  it  does  not 
appear  that  the  point  in  question  is  a  necessary  inference 
from  the  facts  established,  it  is  not  proved,  although  it 
may  have  been  rendered  highly  probable. 

It  is  further  to  be  observed  that  we  are  liable  to  err 
in  drawing  the  inferences  from  the  circumstances  proved, 
and  that  prejudices  are  apt  to  make  the  Imagination  sup- 
ply the  links  that  are  wanting  in  order  to  make  the  chain 
of  evidence  complete,  while  the  facts  are  often  made 
known  to  us  by  testimony,  which  is  liable  to  deceive  us, 
as  in  other  cases.  Sometimes,  also,  the  apparent  signs 
may  have  sprung  from  causes  quite  different  from  those 
by  which  they  are  usually  produced,  as  where  a  stranger 
may  have  been  handling  a  thermometer,  unknown  to  the 
investigator,  or  stolen  goods  are  secretly  conveyed  into 
the  house  of  an  innocent  man,  in  order  to  avert  suspicion 
from  the  thitff.  Sometimes,  on  the  other  hand,  the  usual 
signs  are  removed  or  concealed  either  from  design  or  ac- 
cident, as  where  a  murderer  hides  the  weapon  of  destruc- 


212  EVIDENCE.  [CHAP.  XII. 

tion,  or  a  servant  takes  water  from  a  rain-gauge,  without 
its  being  known. 

The  degree  of  probability  established  by  the  circum- 
stances, depends  on  their  force,  independence,  consisten- 
cy, and  number.  If  several  of  them  are  dependent  on 
one,  or  so  connected  with  it  that  they  must  be  true  if  it 
is  true,  all  are  tantamount  to  one  only :  and,  in  order  to 
entitle  the  circumstances  to  any  weight,  they  must  not 
materially  conflict  with  each  other ;  else  the  inconsistent 
class  will  destroy  the  force  of  the  rest. 

This  kind  of  evidence  is  susceptible  of  every  degree 
of  probability ;  and,  therefore,  we  should  beware  of  either 
receiving  or  rejecting  it  indiscriminately.  Every  case 
should  stand  on  its  own  merits.  The  probability  is  often 
so  strong  that  we  should  unhesitatingly  act  upon  it,  as 
if  it  were  a  certainty,  while  it  is  often  so  much  the  re- 
verse that  it  is  of  no  real  value,  except  to  suggest  the 
course  of  further  investigation. 

§  2.  CRITERIONS  OF  TESTIMONY. — Importance  of  Testimony. — (1) 
Witness  must  have  had  means  of  knowing. — Usual  Requisites. — 
General  and  Special  Testimony. — Means  of  ascertaining  witness's 
Credibility,  on  this  head. — (2)  fie  must  have  paid  Attention. — 
Common  sources  of  Inattention. — Partial  Attention. — Where  this 
point  requires  particular  Consideration. — Means  of  determining  the 
degree  of  attention  given. — (3)  Testimony  must  not  be  corrupted 
by  Bias. — Kinds,  influence,  and  sources  of  Bias. — How  affected  by 
individual  Character. — Indications  of  its  Absence. — Means  of  as- 
certaining its  Existence,  Character,  and  Influence. — (4)  Testimony 
must  not  be  a  doubtful  Inference. — Two  classes  of  Inferences. — 
Various  Sources  of  Error,  and  Means  of  avoiding  them. — (5)  Mem- 
ory must  not  be  in  fault. — Influence  of  Bias  on  Remembrance. — 
Means  of  obviating  its  Defects. — Frequent  Difficulty,  and  means 
of  surmounting  it. — (6)  Witness  must  possess  a  competent  Under- 
standing. —  Children's  Testimony.  — Indications  of  Defect.  — (7) 
Testimony  must  be  free. — Effects  of  Torture,  Threats,  Promises, 
and  Suggestions. — Means  of  ascertaining  whether  they  have  op- 
erated.— (8)  Testimony  must  be  properly  expressed,  and  faithfully 
transmitted. — How  defects  of  this  kind  may  be  discovered. — Con- 
curring Testimonies. — Nature  of  the  Statements. — Common  proof 
of  Invalidity. — Caution. — Discrepancies. — Important  Distinctions. 
— Sources  and  Character  of  apparent  Discrepancies  and  minor  In- 
accuracies.—  Real  and  material  Discrepancies.  —  Means  of  sur- 
mounting Difficulties. — Particular  use  of  Signs. — Probable  Testi- 
mony.— Its  Nature  and  Tests. — Caution. — Influence  and  Effects 
of  Prejudices,  in  judging  of  Testimony. — Various  kinds  of  Proba- 
bilities, and  principles  applicable  to  them.  —  Two  futile  Distinc- 
tions. 

The  subject  of  testimony  is  of  the  utmost  consequence, 


SEC.  2.]  CKITEKIONS  OF  TESTIMONY.  213 

as  by  far  the  greatest  and  most  important  parts  of  hu- 
man knowledge  are  based  on  it ;  and  it  is  also  frequent- 
ly attended  with  difficulty.  Hence  its  principles  demand 
a  diligent  study  and  a  careful  application. 

To  render  the  testimony  of  an  ordinary  witness  con- 
clusive, as  to  the  point  which  it  professes  to  prove,  it  must 
generally  possess  the  following  characteristics. 

1.  The  witness  must  have  possessed  the  means  of  know- 
ing what  he  testifies.  The  thing  declared  to  have  been 
comprehended  must  have  been  within  the  range  of  the 
proper  faculties,  in  circumstances  where  they  could  act 
effectually ;  and  these  must  have  been  in  a  sound  condi- 
tion, or  at  least  not  seriously  deficient  from  disease  or 
natural  defect.  The  dim-sighted  cannot  see  distinctly, 
nor  can  the  deaf  hear  aright.  In  the  case  of  sight,  the 
object  must  not  only  be  sufficiently  near,  but  there  must 
be  enough  of  light,  and  not  much  more:  men  cannot  see 
clearly  in  the  dark ;  and  a  dazzling  glare  of  light  is  equal- 
ly unfavorable  to  proper  vision.  In  the  same  way,  sounds 
may  be  either  too  loud  or  too  low  for  distinct  hearing. 

If  the  requisite  organs  are  sound,  defects  of  others  do 
not  generally  impair  the  testimony.  It  is  no  objection 
to  a  witness's  statement  regarding  what  he  saw,  that  he 
is  deaf.  Indeed  a  defect  of  one  faculty  frequently  con- 
centrates the  attention  so  closely  on  the  objects  of  that 
which  is  sound,  as  to  render  the  comprehension  and  re- 
membrance of  them  unusually  distinct  and  vivid.  It  has 
often  been  observed  that  the  blind  mark  and  remember 
what  they  hear,  and  the  cleaf,  what  they  see,  better  than 
those  who  labor  under  no  such  defect. 

Testimony  is  of  two  kinds,  general  and  special.  The 
former  alleges,  not  the  particular  things  actually  witness- 
ed, but  some  generalization  or  inference  from  them:  the 
latter  states  only  what  was  directly  comprehended.  A 
person  is  incompetent  to  give  a  general  testimony  where 
he  is  not  a  judge  of  the  subject :  but  such  a  restriction 
does  not  apply  to  special  testimony.  Thus,  a  man  who 
is  quite  ignorant  of  seamanship,  is  incompetent  to  testify 
whether  a  ship  of  which  he  was  aboard,  was  worked 
rightly  at  sea,  during  a  tempest :  but  he  may  state  the 
particular  facts  that  he  noticed,  and  aid  mariners  in  form- 
ing a  correct  opinion. 

•  The  credibility  of  a  witness,  on  this  head,  can  be  gen- 
erally ascertained  from  a  knowledge  of  his  circumstances 
when  he  comprehended  what  he  testifies. 


214  EVIDENCE.  [CHAP.  XII. 

2.  The  witness  must  have  sufficiently  attended  to  what 
he  testifies.     If  his  attention  was  absorbed  by  something 
else,  or  if  lie  was  indifferent,  or  so  prejudiced  that  he  did 
not  fairly  observe  the  object,  his  testimony  is  evidently 
unreliable.     A  partial  degree  of  attention  may  enable  a 
witness  to  testify  correctly  regarding  the  main  facts :  but 
in  such  cases  little  reliance  can  be  placed  on  statements 
of  details.    In  order  to  entitle  these  to  credit,  it  must  ap- 
pear that  the  witness  paid  particular  attention  to  the 
subject,  and  that  he  does  not  mistake  for  an  apprehen- 
sion what  was  only  a  conception,  more  especially  if  he 
belongs  to  that  class  of  persons  who  are  apt  to  be  as 
much  occupied  with  what  they  fancy  as  with  what  is 
present  to  their  senses. 

The  degree  of  attention  given  can  be  generally  learn- 
ed, either  from  the  witness's  character  and  tastes,  or 
from  the  nature  of  his  statements.  If  these  are  full,  and 
at  the  same  time  minute,  attention  may  be  inferred, 
while  vagueness  and  confusedness  of  statement  indicate 
inattention,  in  the  absence  of  any  design  to  conceal  or 
mislead. 

3.  The  testimony  must  not  be  wilfully  corrupted  from 
bias.     In  order  to  render  a  testimony  quite  reliable,  the 
witness  must  be  willing  to  relate  the  exact  truth  :  other- 
wise it  will  be  misrepresented  by  suppression,  distortion 
or  false  additions.     The  bias  may  be  either  friendly  or 
hostile.     The  former  leads  a  witness  to  represent  things 
more  favorably  for  the  party  on  whose  behalf  he  testifies 
than  truth  warrants :  the  latter  tends  in  the  contrary  di- 
rection. 

The  sources  of  bias  are  as  numerous  as  the  desires  of 
the  human  mind :  but  the  most  prevalent  are,  self-inter- 
est, ambition,  the  love  of  ease,  the  love  of  the  marvelous, 
vanity,  and  malice.  Strong  party  feelings  seldom  lead  to 
actual  lying,  where  they  are  unaccompanied  by  baser  de- 
sires; but  they  frequently  produce  concealment,  exag- 
geration or  distortion ;  and  hence  the  testimony  of  par- 
tisans is  justly  liable  to  be  suspected  of  such  defects. 

Where  we  are  ignorant  of  a  witness's  character,  we 
should  not  admit  his  unsupported  testimony  as  conclu- 
sive, if  there  is  room  for  the  influence  of  bias :  but  where 
we  know  him  to  be  strictly  veracious,  we  may  receive 
Ins  statements  without  suspicion,  wherever  he  could  err 
only  from  conscious  falsehood.  In  many  instances,  his 


SEC.  2.]  CKITEKIONS  OF  TESTIMONY.  215 

veracity  appears  from  the  accuracy  of  his  statements,  as 
we  learn  from  other  sources,  while  it  is  sometimes  estab- 
lished by  the  evidence  contradicting  his  bias.  Where  a 
witness  testifies  against  the  prejudices  or  cherished  views 
of  himself  or  his  party,  and,  more  especially,  where  he 
exposes  himself  to  pecuniary  loss,  suffering  or  general 
odium,  by  his  testimony,  without  reaping  from  it  any  ad- 
vantage that  could  lead  him  to  falsify,  we  may  consider 
his  statements  sufficiently  free  from  the  influence  of  bias. 
This  conclusion  is  often  corroborated  by  their  exhibiting 
the  artlessness,  straightforwardness,  candor,  precision 
and  minuteness  which  characterize  faithful  testimony, 
just  as  we  often  detect  bias  and  fraud  by  the  contrary 
qualities. 

Where  the  testimony  is  otherwise  unexceptionable, 
but  it  may  possibly  have  been  influenced  by  bias,  we 
should  receive  it  unhesitatingly  only  so  far  as  it  could 
not  have  been  affected  by  the  bias,  and  suspend  any  opin- 
ion as  to  the  rest  of  it  till  we  obtain  further  proof.  Where 
the  witness's  character  is  known,  we  have  only  to  determ- 
ine whether  there  is  any  bias  strong  enough  to  have 
materially  affected  his  testimony. 

The  existence  and  nature  of  the  bias  may  be  frequently 
learned  from  the  witness's  nation,  profession,  party,  age, 
moral  character,  or  peculiar  relation  to  the  testimony,  as 
where  he  was  himself  concerned,  and  is  anxious  to  show 
the  best  phase  of  his  own  conduct,  or  where  some  of  his 
intimate  friends  or  near  relations  are  concerned.  In  oth- 
er cases,  these  are  learned  from  the  sweeping  or  unquali- 
fied nature  of  the  statements,  laudatory  or  contemptuous 
expressions,  and  the  manifest  exaggeration,  extenuation 
or  coloring  of  the  testimony.  Sometimes  they  are  de- 
tected by  comparing  the  statements  with  those  of  an  im- 
partial person,  or  one  of  opposite  bias,  and  by  his  evi- 
dent desire  to  have  us  believe  a  particular  thing. 

Bias  is  sometimes  discovered  from  the  witness's  hesi- 
tating before  making  his  statements,  for  the  manifest 
purpose  of  avoiding  self-contradictions,  and  rendering  his 
falsehoods  plausible.  At  other  times,  it  appears  from  the 
statements  being  vague,  studied,  evasive,  impertinent  or 
flippant,  by  the  witness's  pretending  to  forget  what  he 
could  not  but  remember,  by  his  avoiding  definite  asser- 
tions where  ho  can  be  contradicted  by  other  testimony, 
while  lie  speaks  positively  and  precisely  where  he  cannot, 


216  EVIDENCE.  [<URAP.  XII. 

or  by  his  stating  all  that  makes  in  favor  of  a  certain  con- 
clusion, while  he  suppresses  things  of  a  contrary  tend- 
ency, which  he  must  well  know.  We  should,  however, 
distinguish  the  hesitation  of  bashfulness  from  that  of 
bias,  which  can  generally  be  done  from  observing  the 
witness's  whole  manner,  or  his  relation  to  the  matter  in 
question. 

The  extent  to  which  bias  has  influenced  the  testimony, 
and  the  allowances  to  be  made  for  it,  may  generally  be 
learned  from  the  circumstances  of  the  case,  or  the  testi- 
monies of  other  witnesses ;  and,  in  many  instances,  it  may 
be  ascertained  by  comparing  one  part  of  the  statements 
with  another,  or  with  what  we  previously  knew  of  the 
subject. 

4.  The  thing  asserted  must  not  be  a  doubtful  inference 
from  what  was  actually  witnessed.     Inferences  are  fre- 
quently drawn  with  such  rapidity  that  we  mistake  them 
for  comprehensions,  while  they  are  sometimes  erroneous. 
Hence  witnesses  have  thus  frequently  testified  untruths. 
The  inferences  are  generally  drawn  correctly,  and,  as  was 
formerly  explained,  we  may  admit  them  without  hesi- 
tation.    But  some  extend  such  inferences  beyond  due 
bounds.     They  will  say,  for  instance,  that  they  saw  or 
felt  such  things  when  they  only  apprehended  something 
which  they  believed  to  be  tantamount,  but  which  was,  in 
reality,  very  different.     Biased  and  careless  witnesses  are 
especially  liable  to  fall  into  this  error,  but  it  often  results 
from  a  general  illusion.     Instances  occur  in  the  general 
belief  regarding  our  seeing  the  heavenly  bodies  moving, 
and  the  distances  of  objects. 

Sometimes  a  witness  makes  a  statement  as  if  upon  his 
own  personal  observation,  when,  in  fact,  he  derived  his 
information  wholly  from  others.  Such  testimony,  at  the 
best,  directly  proves  only  what  the  witness  was  told ; 
and  the  accuracy  of  the  transmission  must  be  tested  by 
the  circumstances  attending  it.  The  manifest  relation 
of  the  witness  to  the  thing  testified,  or  the  nature  of  his 
statements,  often  enables  us  to  ascertain  whether  he 
speaks  from  personal  observation ;  and,  in  other  cases, 
this  can  generally  be  learned  either  from  the  witness  him- 
self or  from  other  parties. 

5.  It  must  appear  that  there  is  no  ground  to  suspect  a 
failure  of  Memory.     When  persons  testify  regarding 
things  which  they  witnessed  long  ago,  they  are  very  apt 


SEC.  2.]  CRITEKIONS  OF  TESTIMONY.  217 

either  to  forget  them  altogether,  and  say  they  never  com- 
prehended such  a  thing,  or  to  confound  them  with  what 
they  apprehended  or  imagined  on  some  other  occasion ; 
and  hence,  where  their  testimony  is  unsupported  by  oth- 
er evidence,  it  is  seldom  conclusive,  except  as  to  matters 
which  they  could  neither  forget  nor  mistake.  The  Mem- 
ory of  some,  again,  is  so  feeble,  and  their  Imagination  so 
active,  that  they  can  hardly  distinguish  what  they  re- 
member from  what  they  only  conceived,  after  the  lapse 
of  a  few  days ;  and  hence  their  uncorroborated  testimony 
is  of  little  value.  Persons  of  this  class  are  generally  dis- 
covered by  the  palpable  errors  in  their  testimonies. 

The  bias  and  general  character  of  a  witness  affect  his 
remembrance,  as  well  as  his  apprehension,  because  we 
remember  what  strongly  interests  us  much  better  than 
what  we  view  with  indifference.  Hence  a  witness  fre- 
quently remembers  well  one  part  of  what  he  apprehend- 
ed, and  wholly  forgets  the  rest.  Consequently,  unless  it 
appears  that  the  witness  felt  equally  interested  in  all  that 
he  may  have  apprehended,  his  having  no  recollection  of 
one  part  affords  no  strong  proof  that  it  was  not  present. 

The  immediate  defects  of  a  witness's  Memory  may 
have  been  obviated  in  several  ways.  He  may  have  accu- 
rately written  down  what  he  observed  at  the  time  of  its 
occurrence,  or  before  his  recollection  of  it  failed,  and  he 
may  have  a  distinct  remembrance  that  the  writing  is  full 
and  correct  throughout,  while  he  can  identify  it ;  or  he 
may  have  perused  a  written  statement  made  by  another, 
while  the  occurrences  or  things  witnessed  were  fresh  in 
his  Memory,  and  he  can  still  testify  to  its  accuracy  from 
his  recollection  ;  or  he  may  have  faithfully  related  to  an- 
other person  what  he  witnessed,  before  he  forgot  it,  and 
the  latter  may  still  have  a  perfect  recollection  of  what 
was  thus  communicated  to  him,  or  may  have  written  it 
down  accurately,  when  he  first  heard  it.  In  all  cases  of 
this  kind,  however,  the  various  parts  of  the  chain  of  evi- 
dence must  be  examined  with  care,  in  order  to  avoid 
false  inferences. 

6.  The  witness  must  not  be  deficient  in  understanding. 
The  statements  of  an  idiot,  a  maniac,  or  a  young  child, 
are  generally  as  worthless,  as  those  of  persons  who  labor 
under  a  defect  of  Memory  or  the  organs  of  sense ;  and 
the  testimony  of  one  who  labors  under  some  hallucina- 
tion or  delusion  relating  to  the  matter  in  question,  is 

K 


218  EVIDENCE.  [CHAP.  XII. 

equally  unreliable,  although  his  intellect  may  be  other- 
wise quite  sound. 

A  child's  testimony  is  sometimes  satisfactory  regard- 
ing simple  and  striking  facts  which  fell  under  his  observ- 
ation ;  and  it  frequently  possesses  the  advantage  of  be- 
ing more  free  from  bias  than  that  of  older  persons :  but 
the  inexperience  and  volatile  disposition  of  childhood,  its 
great  liability  to  imposition,  and  its  strong  tendency  to 
mistake  one  thing  for  another,  and  draw  false  inferences, 
generally  render  its  testimony  unsatisfactory,  and  of  lit- 
tle value  except  to  corroborate  other  evidence. 

Where  we  are  not  otherwise  aware  of  the  witness's 
character,  testimonies  of  this  kind  are  usually  detected 
by  their  puerility,  incoherence  or  absurdity. 

7.  The  testimony  must  be  the  free  and  spontaneous 
statement  of  the  witness,  unaffected  by  torture,  force, 
threats,  bribes,  promises,  or  suggestions.     All  these  oper- 
ate like  natural  bias,  and,  in  many  instances,  still  more 
strongly.     It  was  formerly  a  common  practice  to  torture 
witnesses  who  would  not  otherwise  testify,  in  order  to 
extort  the  truth :  but  experience  showed,  what  might 
have  been  easily  foreseen,  that  such  applications  rather 
led  the  witness  to  declare  what  he  knew  was  required, 
in  order  to  be  released  from  the  torture,  even  where  his 
testimony  subjected  him  to  severe  punishment. 

Although  this  may  be  considered  the  extreme  case,  yet 
all  similar  methods  of  eliciting  evidence  are  alike  in  prin- 
ciple, since  they  interfere  with  the  fair  statement  of  what 
the  witness  knows  or  remembers,  and  must  generally  lead 
to  misrepresentation,  if  not  to  positive  misstatement. 
Suggestions  from  Others  are  equally  objectionable,  since 
they  tend  to  make  a  witness  confound  what  he  remem- 
bers with  what  he  only  conceives,  even  where  there  are 
no  suspicions  of  collusion,  which  suggestions  of  this  kind 
naturally  excite. 

The  relations,  circumstances  and  conduct  of  the  par- 
ties concerned,  the  character  of  the  testimony,  or  the  sub- 
sequent free  statements  of  the  witnesses,  generally  ren- 
der it  easy  to  ascertain  whether  motives  of  this  kind  have 
operated;  and,  in  many  cases,  there  is  not  even  any 
ground  to  suspect  them. 

8.  The  testimony  must  be  properly  expressed,  and  con- 
veyed to  us  either  directly,  or  substantially  as  it  was  orig- 
inally delivered.     It  would  evidently  mislead,  either  by 


SEC.  2.]  CRITEKIONS  OF  TESTIMONY.  219 

being  stated  in  language  which,  when  fairly  interpreted, 
conveyed  an  erroneous  signification,  or  by  the  original 
terms  being  essentially  altered,  through  omissions,  addi- 
^tions  or  substitutions.  Defects  of  this  kind  are  to  be  dis- 
'covered  by  observing  the  witness's  character  and  cir- 
cumstances, and  the  mode  in  which  the  testimony  is  trans- 
mitted to  us. 

Where  a  testimony  is  unexceptionable  on  all  the  pre- 
ceding heads,  it  is  evidently  conclusive.  But,  in  many 
cases,  we  have  not  sufficient  information  on  one  or  more 
of  them ;  and  hence  it  is  necessary  to  determine  the  force 
of  the  testimony  on  other  grounds. 

The  concurring  testimony  of  several  independent  wit- 
nesses affords  certainty,  in  many  cases  otherwise  doubt- 
ful. Where  the  statements  of  one,  although  very  unsatis- 
factory when  taken  alone,  are  corroborated  by  many  oth- 
ers, while  there  is  no  reason  to  suspect  collusion  or  un- 
conscious error,  we  justly  consider  the  evidence  con- 
clusive. For  it  is  incredible  that  various  unconnected 
persons,  differently  situated,  should  all  invent  the  very 
same  fictitious  tale,  or  commit  the  very  same  mistake, 
unless  there  is  some  ground  of  illusion  common  to  them 
all ;  and  where  this  exists,  it  is  generally  obvious. 

The  absence  of  collusion  or  forgery  is  frequently  evinced 
by  various  coincidences  in  the  different  testimonies,  which 
are  so  indirect  and  recondite  as  to  satisfy  us  that  they 
could  not  have  resulted  from  any  kind  of  fraud.  These 
frequently  consist  of  incidental  remarks  or  allusions, 
which  are  found  to  tally  with  the  other  testimonies  only 
by  examining  them  closely,  and  drawing  various  infer- 
ences, so  that  it  would  evidently  baffle  human  ingenuity 
to  forge  such  narratives,  and  yet  escape  real  discrepancies. 
This  conclusion  is  sometimes  corroborated  by  the  testi- 
monies exhibiting  several  apparently  glaring  inconsisten- 
cies, which  no  one  capable  of  forging  such  testimonies 
could  have  overlooked,  but  which  can  either  be  recon- 
ciled, or  are  of  such  a  character  as  not  to  invalidate  the 
substantial  accuracy  of  the  evidence. 

The  nature  of  the  statements  often  entitles  them  to  be- 
lief, independently  of  the  witness's  character,  as  where  he 
states  the  results  of  recondite  scientific  investigations,  on 
a  subject  of  which  he  is  ignorant,  or  plans  and  sentiments 
which  are  above  his  power  of  conception,  if  not  above 
his  comprehension.  In  cases  of  this  kind,  the  testimony 


220  EVIDENCE.  [CHAP.  XII. 

is  credible,  because  the  witness  could  not  have  forged  it, 
while  its  consistency  with  what  is  known  from  other 
sources,  may  show  that  the  facts  are  not  materially  mis- 
represented. 

On  the  other  hand,  one  of  the  most  common  means  of' 
ascertaining  the  invalidity  of  a  testimony,  is,  its  being  at 
variance  with  what  we  know  from  other  sources :  for 
truth  cannot  be  inconsistent  with  itself.  Some  state- 
ments are  incredible,  because  they  assert  self-evident  im- 
possibilities ;  and  others  are  so,  because  they  are  incon- 
sistent with  conclusive  proof.  But  we  must  beware  of 
hastily  assuming  that  this  is  the  case,  especially  where 
the  witness's  character  is  otherwise  good :  for  we  are 
very  apt  to  be  satisfied  with  fallacious  proof  of  what  we 
wish  to  be  true ;  and  cases  are  not  rare  in  which  conclu- 
sive testimony  has  been  rejected,  on  the  ground  that  it 
contradicted  known  truth,  when,  in  fact,  it  contradicted 
only  cherished  errors. 

In  some  instances,  the  worthlessness  of  the  testimony 
is  apparent  from  the  fact  that  one  part  of  it  directly  con- 
tradicts another,  on  points  of  great  importance.  This 
contradiction  may  exist  between  the  different  parts  of 
one  statement,  or  a  Avitness's  present  allegations  and  for- 
mer statements  which  he  made  on  the  same  subject ;  or 
it  may  lie  in  the  conflicting  statements  of  different  wit- 
nesses. Here  we  must  distinguish  between  material  dis- 
crepancies, which  proceed  from  gross  carelessness,  for- 
getfulness  or  unfaithfulness,  and  those  minor  variations 
which  generally  exist  in  the  testimonies  of  independent 
witnesses,  or  even  between  the  different  statements  of 
the  same  witness.  The  former  invalidate  a  witness's 
credibility,  while  the  latter  do  not,  but  frequently  estab- 
lish it. 

Mendacity,  collusion  and  forgery  are  frequently  de- 
tected by  the  absence  of  any  palpable  inconsistency  with 
the  belief  of  the  person  addressed,  while  a  careful  and 
extensive  scrutiny  will  discover,  in  the  different  state- 
ments, serious  violations  of  truth.  A  faithful  witness, 
on  the  other  hand,  often  makes  statements  which  do  not 
precisely  tally  with  the  opinions  of  those  whom  he  ad- 
dresses, or  possibly  even  with  all  his  own  allegations. 
But  their  substantial  accuracy  is  generally  confirmed  by 
subsequent  investigations  and  discoveries.  At  the  same 
time  these  detect  a  false  testimony,  since  every  error  is 


SEC.  2.]  DISCREPANCIES.  221 

necessarily  inconsistent  with  some  truth,  which  future 
researches  or  accidental  discoveries  generally  bring  to 
light.  So  numerous  are  the  sources  which  gradually  re- 
veal error  or  falsehood,  by  unfolding  some  truth  which 
is  inconsistent  with  it,  that  it  is  very  frequently  exploded 
by  the  gradual  disclosures  of  time. 

Many  discrepancies  are  only  apparent,  and  arise  from 
our  misunderstanding  or  misinterpreting  part  of  the  tes- 
timony ;  some  proceed  from  a  witness's  stating  as  a  fact 
a  false  inference  which  he  drew  from  what  he  compre- 
hended ;  while  others  spring  from  one  witness  relating 
what  another  overlooked  or  forgot,  every  one  generally 
remembering  only  what  interested  him,  or  attracted  his 
attention.  Some  proceed  from  one  witness  suppressing 
part  of  what  he  apprehended,  for  reasons  which  can  gen- 
erally be  discovered,  without  much  difficulty,  by  consid- 
ering his  circumstances  and  character. 

Many  real  discrepancies  rather  confirm  than  invalidate 
the  testimony,  because,  while  they  are  of  very  little  con- 
sequence, they  indicate  the  absence  of  studied  and  fraud- 
ulent harmony.  So  numerous  are  the  sources  of  error, 
that  the  entire  absence  of  any  variations  regarding  such 
matters  as  dates,  places  and  numbers,  is  not  to  be  ex- 
pected, under  ordinary  circumstances ;  and,  therefore, 
such  variations  do  not  generally  affect  a  witness's  credi- 
bility regarding  the  main  points  of  his  testimony,  espe- 
cially when  they  are  elicited  by  brow-beating  bashful  or 
timid  witnesses.  Discrepancies  between  different  state- 
ments of  the  same  witness  often  arise  from  a  mere  slip 
of  the  tongue  or  pen,  or  some  other  slight  .degree  of  in- 
attention, or  a  failure  of  memory  regarding  points  of  no 
consequence,  or  misinformation  derived  from  others,  so 
that  they  do  not  in  the  least  affect  his  veracity,  and  ought 
to  have  little  influence  on  his  credibility. 

Where  testimony  is  really  contradictory  or  discrepant, 
on  material  points,  we  may  either  look  for  further  evi- 
dence, or  closely  scrutinize  the  statements  and  character 
of  the  witnesses.  We  shall  thus  generally  find  an  ab- 
sence of  the  marks  of  conclusiveness  on  one  side  or  the 
other.  The  defect  is  often  so  manifest  as  to  render  the 
testimony  on  that  side  worthy  of  no  regard.  The  state- 
ments of  a  veracious  and  careful  witness  are  not  in  the 
least  invalidated  by  their  being  contradicted  by  those  of 
a  notorious  liar  or  fabulist.  So,  when  one  witness  of 


222  EVIDENCE.  [CHAP.  XII. 

doubtful  veracity  states  something  which  is  omitted  by 
another,  of  known  credibility,  and  which  the  latter  could 
have  neither  overlooked  nor  forgotten,  the  former  state- 
ment should  be  disregarded. 

If  the  difficulty  cannot  be  removed  by  any  of  those 
means,  we  can  obtain  only  a  probability,  and  not  knowl- 
edge, unless  we  have  recourse  to  better  evidence,  which 
we  should  always  do,  if  practicable,  in  every  case  of  dif- 
ficulty. 

The  credibility  of  a  statement  may  often  be  ascertained 
from  the  witness's  former  conduct.  The  characters  of 
men  are  generally  so  uniform  and  consistent,  that  one 
who  lied  yesterday  is  seldom  found  to  be  veracious  to- 
day, and  one  who  has  been  strictly  veracious  hitherto, 
will  generally  be  found  so  hereafter.  If  a  man  has  been 
found  to  adhere  to  truth,  amid  the  strongest  temptations 
to  the  contrary,  and  to  have  been  constantly  guided  by 
rigid  principles  of  veracity,  we  may  safely  believe  his 
statements,  provided  he  has  not  been  misled.  But  if  he 
is  found  to  have  generally  yielded  to  strong  temptations, 
although  he  may  be  veracious  in  ordinary  circumstances, 
we  can  trust  his  unsupported  statements  only  when  there 
is  no  strong  motive  to  falsify.  If  he  has  habitually  lied, 
no  dependence  can  be  placed  on  his  testimony  except 
where  there  is  evidently  no  possible  motive  for  falsehood, 
which  can  seldom  be  safely  assumed  of  such  characters. 

The  credibility  of  a  witness  may  sometimes  be  ascer- 
tained by  observing  how  he  states  facts  with  which  we 
"arc  acquainted  from  other  sources,  and  which  form  tests 
of  his  veracity,  such  as  accounts  of  things  discreditable 
to  himself  or  his  party,  or  things  which  militate  against 
some  of  his  favorite  opinions  or  desires.  But  we  must 
beware  of  trusting  to  doubtful  testimony  regarding  a 
witness's  character :  for  we  sometimes  receive  the  most 
contradictory  accounts  of  a  person's  veracity,  and  it  is 
folly  to  believe  one  stranger  regarding  the  character  of 
another,  where  he  may  have  some  motive  for  misrepre- 
sentation. 

When  a  testimony  amounts  only  to  a  probability,  signs 
often  supply  the  deficiency,  and  produce  certainty.  If  a 
stranger  asserts  that  there  has  been  a  severe  earthquake, 
at  a  particular  time  and  place,  his  testimony  may  be  con- 
firmed by  palpable  marks  of  its  eifects,  such  as  rents  in 
the  ground  and  fallen  houses.  In  such  cases  signs  either 


SEC.  2.]  PROBABILITIES.  223 

corroborate  or  refute  the  testimony,  precisely  like  the 
statements  of  additional  witnesses.  They  may  simply  af- 
fect its  degree  of  probability ;  or  they  may  render  it  con- 
clusive on  the  one  hand,  or  entirely  invalidate  it  on  the 
other. 

The  probability  of  a  testimony  of  this  kind  depends  on 
the  witness's  circumstances  and  character.  If  he  had 
good  means  of  knowing  the  truth,  and  bears  a  fair  repu- 
tation, there  is  a  great  probability  that  his  testimony  is 
true.  But  if  his  situation  was  unfavorable,  and  his  ve- 
racity is  very  doubtful,  his  statements  cannot  be  safely 
adopted,  without  corroborative  evidence.  If  his  state- 
ments have  received  a  coloring  from  his  prejudices,  we 
should  endeavor  to  ascertain  its  extent,  and  make  due 
allowances. 

If  there  are  several  independent  witnesses,  the  proba- 
bility will  vary  according  to  their  number,  their  several 
characters  and  opportunities,  the  degree  of  attention 
they  bestowed  on  the  matter,  the  time  that  elapsed,  and 
so  forth.  The  probability  may  be  so  strong  that  we  are 
justified  in  acting  as  if  it  were  a  truth ;  yet  we  should 
beware  of  ever  assuming  it  to  be  such,  and  rejecting, 
without  due  examination,  any  alleged  proof  which  seems 
to  contradict  or  impugn  it.  Proof  should  never  be  re- 
jected wherever  we  do  not  already  possess  certain  knowl- 
edge :  for  it  frequently  happens  that  the  highest  proba- 
bilities are  refuted  by  irrefragable  proof. 

Mankind  are  apt  to  be  greatly  influenced,  in  the  re- 
ception of  testimony,  by  their  views  regarding  its  extrin- 
sic probability,  or  that  which  is  based  on  the  nature  of 
the  statements:  but  this  is  generally  the  effect  of  preju- 
dice. The  unlearned  frequently  measure  everything  by 
their  personal  experience ;  and  the  learned  often  view 
subjects  in  the  light  of  their  own  theories.  Hence  con- 
clusive testimony  has  often  been  rejected,  simply  because 
it  contradicted  the  erroneous  belief  or  strong  desires  of 
the  party  to  whom  it  was  addressed,  while,  owing  to  the 
same  causes,  worthless  testimony  was  received  as  con- 
clusive. Some  travelers  have  been  deemed  liars,  for 
faithfully  recording  what  they  saw,  while  others  have  re- 
lated fictions,  which  were  believed  without  doubt  or  hes- 
itation. 

Unexceptionable  testimony  is  never  to  be  rejected  on 
account  of  the  apparent  improbability  of  the  statement: 


224  EVIDENCE.  [CHAP.  XII. 

for  testimony  can  prove  anything  comprehensible,  which 
is  not  self-evidently  impossible,  or  demonstrably  incon- 
sistent with  known  facts ;  and,  for  such  propositions,  no 
unexceptionable  testimony  ever  can  be  given,  for  the  sim- 
ple reason  that  incompatibilities  cannot  co-exist.  But 
we  must  beware  of  heedlessly  assuming  that  anything 
professedly  proved  by  reliable  testimony,  belongs  to  this 
class :  for  prejudice  is  apt  to  make  us  infer  that  a  propo- 
sition is  absurd  or  untenable,  when,  in  truth,  it  is  only 
distasteful  to  our  wishes,  or  incompatible  with  our  erro- 
neous opinions. 

Men  have  often  admitted  errors  on  inadequate  testi- 
mony, because  they  appeared  to  them  highly  probable, 
while  they  rejected  important  truths,  proved  by  conclu- 
sive testimony,  simply  because  they  appeared  highly  im- 
probable, which  was  confounded  with  what  is  impossi- 
ble. The  proper  course  is,  never  to  admit  anything  as  a 
certain  fact,  whether  probable  or  not,  when  the  evidence 
is  unsatisfactory,  and  never  to  reject  anything  which  is 
proved  by  unexceptionable  evidence,  however  contrary 
to  our  preconceived  opinions  or  our  wishes.  To  act  oth- 
erwise is,  to  believe  without  any  good  ground  on  the 
one  hand,  and  to  disbelieve  against  conclusive  proof  on 
the  other.  The  very  improbability  of  a  statement  is  oft- 
en a  strong  indication  of  its  truth,  since  a  liar  would  in- 
vent something  more  likely  to  be  believed  by  those  whom 
he  addressed,  and  an  honest  and  careful  witness  is  more 
apt  to  pay  particular  attention  to  an  extraordinary  phe- 
nomenon than  to  one  of  a  different  character. 

Where,  however,  the  testimony  is  not  conclusive,  and 
it  only  establishes  a  probability,  we  may  set  up  another 
probability  in  opposition  to  it,  and  thus  possibly  nullify 
its  whole  force. 

The  intrinsic  improbability  of  a  testimony,  or  that 
which  flows  from  the  witness's  circumstances  and  char- 
acter, must  be  carefully  distinguished  from  its  extrinsic 
improbability,  or  that  which  is  based  on  the  nature  of 
the  thing  testified.  Where  the  former  does  not  exist, 
the  latter  is  entitled  to  no  weight :  otherwise  this 
strengthens  the  former,  or  impugns  an  intrinsic  proba- 
bility, to  a  degree  proportional  to  its  force.  Where  the 
extrinsic  improbability  conflicts  with  the  intrinsic  prob- 
ability, the  resultant  probability  is  equal  to  the  excess 
of  the  weaker  of  these  two  elements  over  the  stronger. 


SEC.  2.]  FUTILE  DISTINCTIONS.  225 

A  distinction  has  been  drawn  between  such  things 
as  are  "  contrary"  and  those  which  are  "  not  conforma- 
ble" to  our  experience ;  and  it  has  been  maintained  that 
evidence  of  the  latter  is  admissible,  but  not  of  the  former. 

To  render  this  distinction  valid,  it  is  necessary  to  make 
the  phrase  "  contrary  to  experience"  mean  that  we  were 
actually  present,  in  the  case  alleged,  and  experienced  no 
such  thing  as  is  affirmed,  while  we  were  so  situated  that 
we  must  have  done  so,  if  it  actually  occurred.  But  the 
distinction  would  now  be  irrelevant,  since  it  amounted 
to  saying  that  we  should  not  receive  another's  testimony, 
to  contradict  what  we  ourselves  properly  witnessed,  a 
doctrine  which,  though  unquestionably  sound,  is  evident- 
ly foreign  to  the  point. 

Another  meaning  of  the  dogma  is,  that  we  experi- 
enced nothing  like  what  is  alleged,  while  we  were  placed 
in  circumstances  where  that  might  be  reasonably  ex- 
pected. In  this  sense,  it  is  evidently  absurd.  It  would 
require  a  man,  for  instance,  who  had  seen  innumerable 
mountains,  to  reject  all  testimony  as  to  the  existence  of 
volcanoes,  because  he  had  never  seen  a  mountain  pour- 
ing forth  fire  or  smoke.  So,  it  would  require  us  to  re- 
ject all  testimony  regarding  the  fall  of  showers  of  stones, 
because  we  have  seen  many  showers  fall,  but  never  one 
of  that  kind. 

The  only  other  admissible  meaning  is,  that  the  thing 
alleged  is  contrary  to  the  experience  of  ourselves  and  all 
our  friends  and  neighbours.  This  modification  is  not 
sounder  than  the  former,  as  these  persons'  circumstances 
are  generally  the  same  as  our  own,  so  far  as  regards  the 
matter  in  question.  The  fact  that  all  our  neighbours  have 
uniformly  seen  the  Sun  in  the  south  at  noon,  by  no  means 
proves  that  others  do  not  see  it  in  the  north,  at  that  time 
of  day.  The  absurdity  of  the  distinction,  taken  in  this 
sense,  is  well  illustrated  by  the  case  of  the  culprit,  who 
offered  to  bring  thirty  witnesses,  every  one  of  whom 
could  truly  swear  that  they  had  never  seen  him  commit 
the  crime  for  which  he  was  on  trial,  after  three  unexcep- 
tionable eye-witnesses  had  sworn  to  the  contrary,  the 
difference  between  the  two  classes  being,  that  the  latter 
were  present,  and  the  former  absent. 

The  sense  which  would  include,  under  the  expression 
"  our  experience,"  that  of  every  individual  of  mankind, 
is   evidently  inadmissible,  as  in  that  case  the  dogma 
K  2 


226  EVIDENCE.  [CHAP.  XII. 

would  assume  that  the  testimony  is  false,  which  was  the 
very  thing  in  question. 

A  similar  distinction  has  been  drawn  between  improb- 
abilities based  on  previous  experience,  and  those  founded 
on  the  various  ways  in  which  a  thing  may  happen.  The 
former  class,  it  has  been  said,  are  not  legitimate  subjects 
of  testimony,  but  the  latter  are.  It  is  sufficient  to  ob- 
serve that  History  abounds  with  instances  of  things  ex- 
tremely different  from  what  previous  experience  would 
have  led  us  to  expect ;  and,  therefore,  this  distinction  is 
as  futile  as  the  former. 

§  3.  VARIOUS  KINDS  OF  TESTIMONY,  AND  PECULIARITIES  OF  EACH. — 
(1)  Explicit  and  Implicit  Testimony. — Advantages  of  each. — (2) 
Immediate  and  Mediate  Testimony. — Characteristics  of  the  latter. 
— Why  common  Rumor  is  generally  worthless. — When  important. 
— Mode  of  testing  the  value  of  Mediate  Testimony. — (3)  Oral  and 
Written  Testimony. — Advantages  and  Disadvantages  of  the  former. 
— Importance  and  Advantages  of  Written  Testimony. — Effects  of 
Lapse  of  Time. 

1.  Testimony  is  explicit  when  it  expressly  declares  the 
very  thing  in  question :  it  is  implicit  when  it  only  states 
something  which  directly  implies  it,  or  is  a  sign  of  it. 
In  the  latter  case,  the  witness  is  sometimes  unaware  of 
the  implication :  and  hence  it  often  elicits  truths  which 
could  be  discovered  in  no  other  way,  owing  to  the  wit- 
ness's strong  desire,  or  fixed  determination,  to  conceal 
them :  and  such  evidence  here  possesses  the  further  ad- 
vantage of  excluding  the  influence  of  bias,  in  coloring 
the  statements,  even  where  there  is  no  attempt  at  con- 
cealment.    Yet,  where  there  is  no  difficulty  of  this  kind, 
explicit  testimony  possesses  the  great  advantage  of  being 
free  from  the  risk  of  false  inferences,  to  which  we  are  al- 
ways more  or  less  liable  in  the  other  case. 

2.  Immediate  testimony  is,  where  the  party  who  ad- 
dresses us  personally  comprehended  what  he  relates: 
mediate  is  that  given  by  one  who  only  heard  or  read 
what  he  relates ;  and  many  parties  may  have  intervened, 
between  the  original  witness  and  the  last  relater. 

As  men  are  generally  liable  to  forget  or  misunder- 
stand what  they  have  read  or  heard,  mediate  testimony 
is  seldom  entitled  to  credit,  especially  where  it  has  passed 
through  many  hands.  It  often  contains  a  large  admix- 
ture of  truth:  but  it  is  frequently  difficult  to  determine, 
with  any  great  degree  of  certainty,  which  part  is  true 


SEC.  3.]  DIFFERENT  KINDS.  227 

and  which  is  false.  Even  the  most  important  part  is 
sometimes  entirely  lost,  or  totally  misrepresented.  Hence 
the  proverbial  uncertainty  of  common  rumor. 

Mediate  testimony  is  particularly  worthless  where,  as 
frequently  happens,  some  of  the  relaters  labor  under  any 
of  the  difficulties  which  invalidate  immediate  testimony, 
as  where  an  unprincipled  man  hears  something  disrep- 
utable about  one  whom  he  strongly  dislikes.  But  the 
immediate  relater  is  sometimes  a  person  of  a  different 
character ;  and  hence  the  muddy  channel  through  which 
the  statements  have  flowed  is  apt  to  be  hidden  from 
view. 

Where  the  .object  is,  merely  to  ascertain  what  com- 
mon report  says,  such  testimony  is  sometimes  quite  im- 
portant, as  where  a  man  prosecuted  for  slandering  an- 
other, shows  that  the  latter's  reputation,  as  to  the  mat- 
ter in  question,  was  previously  very  bad. 

In  estimating  the  value  of  mediate  testimony,  we  must 
first  determine  the  degree  of  credit  due  to  the  immediate 
relater,  and  afterwards  examine  every  part  of  the  chain 
of  evidence.  If  we  find  a  material  defect  in  any  link,  it 
establishes,  at  the  best,  no  more  than  a  probability,  which 
must  be  sufficiently  corroborated  by  some  other  evidence, 
before  it  is  entitled  to  be  received  as  satisfactory. 

Where  a  narrative  includes  both  kinds  of  testimony, 
every  part  is  to  be  tested  by  the  proper  criterion ;  and 
it  may  thus  be  found  that  some  parts  are  quite  credible, 
and  others  as  much  the  reverse.  Herodotus'  account  of 
the  Persian  wars  is  mostly  credible,  because  he  obtained 
his  information  from  eye-witnesses :  but  this  cannot  be 
said  of  his  history  of  earlier  transactions,  which  is  much 
less  reliable. 

3.  Oral  testimony  is  given  by  word  of  mouth :  written, 
is  that  of  a  person  who  is  not  present,  and  whose  written 
statements  are  read.  The  former  possesses  the  advantage 
of  allowing  us  to  observe  the  witness's  demeanor,  and  to 
obtain  further  information,  or  an  explanation  of  difficult- 
ies, by  means  of  questions.  Suitable  interrogations  also 
enable  us,  in  many  instances,  to  test  the  witness's  com- 
petency, and  the  character  of  his  previous  statements. 

On  the  other  hand,  the  presence  and  appearance  of  a 
witness  not  unfrequently  excites  prejudices  which  lead 
to  his  statements  being  estimated  either  above  or  below 
their  real  value,  whereas  a  careful  consideration  of  his 


228  EVIDENCE.  [CHAP.  XII. 

testimony,  by  the  light  of  other  reliable  evidence,  and  a 
knowledge  of  his  character  and  peculiar  circumstances, 
would  obviate  any  such  result.  Immediate  oral  testi- 
mony, also,  can  be  procured  only  during  the  original  wit- 
ness's lifetime,  after  which  the  advantages  of  this  kind 
of  testimony  are  lost. 

Written  or  printed  testimony  can  be  accurately  com- 
municated to  distant  times  and  places,  while  it  obviates 
the  numerous  errors  arising  from  failures  of  memory,  and 
enables  us  to  contemplate  the  statements  as  often  and  as 
deliberately  as  we  please.  It  also  enables  us  to  have  re- 
course to  the  original  evidence,  instead  of  relying  on  hear- 
say, compilations  or  abridgements,  all  of  which  are  liable 
to  produce  numerous  errors,  and  which  frequently  mis- 
represent or  suppress  something  of  importance. 

There  is  generally  less  room  for  bias  in  written  testi- 
mony, because  the  witness's  prejudices  are  not  so  exten- 
sively concerned.  An  author  frequently  writes  for  dis- 
tant times  and  places,  or  at  least  for  unknown  readers ; 
and,  therefore,  he  is  less  tempted  to  misrepresent  than 
where  his  testimony  has  an  evident  bearing  on  immediate 
objects  of  desire,  which  may  be  secured  by  it. 

Another  advantage  of  written  narratives  is,  that  other 
evidences  by  which  they  may  be  tested,  are  more  inde- 
pendent, and  consequently  more  free  from  bias.  The 
people  of  a  neighbourhood  are  all  frequently  influenced 
by  the  same  prejudices,  which  is  rarely  the  case  with  wit- 
nesses who  live  in  distant  ages  and  countries.  The  lapse 
of  time  tends  to  confirm  true  statements  and  disprove 
others,  by  revealing  things  which  confirm  the  former  and 
disprove  the  latter,  while  these  are  so  unconnected  and 
varied,  that  collusion,  or  accidental  errors  of  any  great 
consequence,  are  inevitably  detected.  Thus,  ancient  tes- 
timonies, which  are  corroborated  by  the  successive  dis- 
coveries of  distant  ages  and  countries,  become  more  and 
more  irrefragable  as  they  become  older,  while  false  state- 
ments are  gradually  seen  in  their  true  light. 

While  written  testimony  is  of  such  great  importance, 
it  is  sometimes  attended  with  difficulties  from  which  oral 
evidence  is  generally  free.  These  we  shall  briefly  dis- 
cuss in  the  following  section. 

§  4.  MEANS  OP  ASCERTAINING  THE  ORIGIN  AND  CHARACTER  OF 
WRITTEN  TESTIMONY. — (1)  External  and  Internal  evidences  of 
Authorship. — In  what  cases  the  former  are  reliable,  and  in  what, 


SEC.  4.]  EVIDENCE  OP  AUTHORSHIP.  229 

not. — Principles  of  decision  regarding  the  latter. — Means  of  ascer- 
taining the  Witness's  Age  and  Country. — Important  Requisite. — 
Means  of  distinguishing  spurious  from  genuine  Compositions. — 
When  it  is,  and  when  it  is  not,  of  consequence  who  wrote  a  Com- 
position.— Rules  for  ascertaining  the  Writer,  in  the  former  case. — 
(2)  Sources  of  material  Corruptions. — Rules  for  determining  what 
parts  are  corrupted  or  spurious,  and  what,  genuine. — Different  Edi- 
tions.— ,How  Abridgements  may  be  distinguished  from  Originals. — 
Means  of  ascertaining  the  Age  and  Country  in  which  a  Manuscript 
was  written,  or  a  Book  printed. — (3)  Origin  of  Various  Readings. 
— Where  one  only,  and  where  several,  are  genuine. — Comparative 
purity  of  Manuscript  and  Printed  Copies. — Effects  of  Time,  in  re- 
moving Errors. — Influence  of  Printing. — Rules  regarding  Various 
Readings. — General  Character  of  these  Readings. — (4)  Means  of 
distinguishing  authentic  from  fictitious  narratives. — Applications  of 
this  section. 

I.  The  evidences  of  the  authorship  of  a  composition 
are  either  external  or  internal.  The  former  consists  of 
the  testimony  of  contemporaries  or  persons  who  lived 
near  the  period :  the  latter  is,  that  which  is  afforded  by 
the  matter  and  style  of  the  production. 

External  evidence  is  to  be  examined  like  any  other 
testimony.  In  the  case  of  contemporary  or  very  recent 
writings,  it  is  generally  conclusive,  and  free  from  any  se- 
rious difficulty,  as  there  is  direct  credible  testimony :  but, 
in  regard  to  ancient  compositions,  it  is  often  worthless, 
owing  either  to  the  witness  not  living  sufficiently  near 
the  time  when  the  work  was  composed,  or  to  the  testi- 
mony being  spurious,  or  to  the  known  mendacity  or  in- 
accuracy of  its  author. 

This  testimony  may  consist  either  of  direct  statements, 
or  of  allusions,  quotations  or  translations.  As  a  book 
cannot  be  quot'ed  or  translated  till  it  exists,  the  fact  of 
such  references  being  found  proves  that  the  composition 
is  older  than  the  one  which  contains  the  references.  But 
these  should  be  unequivocal ;  and  the  age  and  origin  of 
the  work  which  contains  them  'should  be  well  known : 
otherwise  they  will  rather  mislead  than  enlighten. 

The  supposed  author  himself  sometimes  testifies  re- 
garding a  composition  attributed  to  him:  but  his  evi- 
dence should  be  received  with  caution :  for  some  dishon- 
est men  have  claimed  the  works  of  others  as  their  own, 
while  some  have  denied  their  real  compositions.  If  the 
author's  veracity  is  unimpeachable,  however,  such  testi- 
mony is  conclusive. 

The  internal  evidence  is  based  on  the  various  peculiar- 


230  EVIDENCE.  [CHAP.  XII. 

ities  of  thought  and  expression  which  distinguish  differ- 
ent ages,  countries,  and  individuals.  A  work  which  bears 
the  characteristic  and  peculiar  indications  of  a  certain 
age  and  country,  may  fairly  be  inferred  to  belong  to 
them,  while  one  which  lacks  these,  may  be  safely  taken 
to  belong  to  some  other  time  and  place. 

The  evidence  afforded  by  particular  allusions  is  often 
conclusive,  as  to  the  time  after  which  a  work  must  have 
been  written.  A  treatise  on  the  Trojan  War,  that  al- 
luded to  the  Crusades,  must  have  been  written  after  the 
tenth  century ;  and  one  which  mentions  the  presidents  of 
the  United  States  of  North  America,  cannot  be  older 
than  the  end  of  the  eighteenth.  It  is  possible,  however, 
that  a  work  may  have  been  altered,  so  as  to  contain  al- 
lusions to  things  much  more  recent  than  the  original 
treatise.  If  the  part  containing  the  allusion  is  genuine, 
its  evidence  is  conclusive :  if  not,  the  age  of  the  compo- 
sition must  be  ascertained  by  other  means. 

The  author's  country  may  often  be  determined  in  a 
similar  manner,  because  some  nations  were  ignorant  of 
things  well  known  to  others.  A  history  of  the  Crusades 
could  not  have  been  written  by  a  Japanese  contempora- 
ry ;  nor  could  a  Roman  history  have  proceeded  from  an 
ancient  Hindoo. 

The  application  of  the  preceding  principles  requires  an 
accurate  knowledge  of  the  real  peculiarities  of  the  differ- 
ent ages  and  countries,  which  were  not  always  such  as 
they  have  been  represented. 

Compositions  of  which  the  authors  are  doubtful  or 
unknown,  have  been  mostly  assigned  to  persons  of  whom 
we  possess  some  genuine  works :  and,  therefore,  we  can 
compare  the  composition  in  question  with  the  latter. 
But,  in  so  doing,  we  should  beware  of  assuming  that  all 
the  works  of  an  author  must  be  precisely  alike,  in  every 
respect.  His  subject,  time  of  life,  and  varying  circum- 
stances and  opinions,  often  produce  marked  diversities 
in  an  author's  different  works,  although  certain  peculiar- 
ities are  generally  common  to  them  all.  We  should, 
therefore,  observe  whether  the  differences  in  question 
are  greater  than  may  reasonably  be  attributed  to  those 
sources. 

The  difficulty  of  detecting  some  spurious  productions 
is  increased  by  their  having  been  designedly  composed 
in  imitation  of  the  alleged  author's  real  works,  and  their 


SEC.  4.]  EVIDENCE  OF  AUTHORSHIP.  231 

consequently  adhering  closely  to  his  style  and  sentiments. 
But  a  close  inspection  will  generally  show  their  different 
origin.  It  is  more  difficult  to  imitate  a  person's  style 
exactly,  throughout  a  composition  of  any  length,  than  to 
mimic  his  voice.  The  imitation  will  be  either  a  spiritless 
copy  of  the  original,  as  unlike  as  a  corpse  is  to  the  living 
person ;  or  it  will  exaggerate  his  peculiarities,  so  as  to 
resemble  a  caricature. 

If  the  imitator  is  incessantly  on  his  guard  against  any 
expression  which  would  betray  him,  his  composition  will 
necessarily  exhibit  a  constrained  and  affected  mode  of 
speaking,  reminding  us  of  a  person  walking  on  stilts, 
with  an  absence  of  originality  and  the  ease  which  distin- 
guishes one  who  uses  his  own  natural  style.  If,  on  the 
other  hand,  he  should  venture  on  new  ground,  and  adopt 
some  freedom  of  expression,  his  own  peculiarities  will 
appear,  and  some  words  will  escape  him  which  will  at 
once  betray  the  origin  of  the  composition. 

The  question  who  actually  wrote  a  composition  is  fre- 
quently of  no  consequence.  For,  even  where  the  author 
employed  an  amanuensis  or  one  who  wrote  from  his  dic- 
tation, we  may  fairly  presume  that  he  either  perused  it 
himself  or  that  it  was  read  over  to  him,  and  all  serious 
errors  corrected,  before  it  passed  out  of  his  hands.  But 
this  question  becomes  very  important  wherever  the  writer 
must  have  been  the  author,  as  it  then  becomes  identical 
with  that  of  authorship,  which  it  may  be  the  principal 
means  of  ascertaining.  In  such  cases,  there  are  the  four 
following  ways  of  ascertaining  the  writer. 

1.  His  own  acknowledgement,  which  is  quite  satisfac- 
tory wherever  his  character  and  motives  are  above  sus- 
picion, and  he  gives  his  evidence  "unambiguously ;  but, 
in  other  cases,  it  may  be  entitled  to  very  little  weight. 

2.  The  evidence  of  a  person  who  saw  him  write  it, 
which  is  to  be  examined  like  other  cases  of  testimony. 

3.  The  opinion  of  one  who  is  familiar  with  the  hand- 
writing.    As  various  persons  often  write  like  each  other, 
and  the  same  person  often  writes  in  different  hands,  either 
from  hurry,  design,  or  gradual  change,  this  evidence  is 
seldom  quite  satisfactory ;  and  it  generally  furnishes  only 
a  probability. 

4.  The  opinion  of  one  who  is  a  judge  of  handwritings, 
and  who  compares  the  writing  in  question  with  others, 
the  writers  of  which  are  supposed  to  be  known.     This 


232  EVIDENCE.  CHAP.  XII. 

method  is  still  less  reliable  than  the  last,  since  we  are 
apt  to  err  regarding  the  origin  of  the  writings  used  for 
comparison ;  and  the  opinion  of  one  who  is  not  familiar 
with  the  party's  handwriting  is  less  reliable  than  that  of 
a  person  who  knows  it  well. 

II.  Written  testimony  has  sometimes  been  materially 
corrupted  from  design.  In  some  instances,  the  corrtipter 
believed  that  he  was  correcting  the  testimony,  and  re- 
moving errors,  while  he  was  only  falsifying  it :  in  other 
cases,  he  acted  wilfully,  from  a  desire  to  make  it  con- 
formable to  his  wishes.  Here  parts  which  exhibit  any 
of  the  three  following  characteristics  are  to  be  rejected 
as  interpolations. 

1.  Where  they  do  not  exist  in  any  good  manuscript, 
or  in  any  printed  edition  superintended  by  the  author. 

2.  Where  the  statements  could  not  possibly  have  been 
made  by  the  author  of  the  work,  on  account  either  of 
his  circumstances  or  his  character. 

3.  Where  we  have  conclusive  external  evidence  that 
the  parts  are  either  wholly  spurious  or  materially  altered. 
Such  evidence  may  be  found  in  the  testimony  either  of 
the  author  himself  or  of  persons  who  derived  their  in- 
formation directly  from  him,  or  examined  a  copy  of  the 
work  known  to  be  correct. 

A  part  is  to  be  deemed  genuine  in  the  following  cases, 
provided  there  is  no  conclusive  proof  to  the  contrary. 

1.  Where  it  is  found  in  all  good  manuscripts,  or  in  a 
manuscript  or  printed  copy  examined  by  the  author. 

2.  Where  there  is  conclusive  external  evidence  of  its 
genuineness.     This  may  be  found  in  the  author's  ac- 
knowledgement, either  direct  or  indirect,  (as  by  quoting 
it  or  alluding  to  it)  or  in  the  statements  of  parties  who 
read  or  heard  the  original  or  obtained  reliable  informa- 
tion from  those  who  knew. 

3.  Where  it  forms  an  essential  part  of  the  composi- 
tion, which  would  be  rendered  unmeaning  or  absurd  by 
its  removal. 

Some  variations  are  possibly  alterations  made  by  the 
author,  in  successive  issues,  in  which  case  widely  differ- 
ent copies  may  all  be  equally  genuine,  although  the  latest 
may  be  fairly  presumed  to  be  the  best.  In  printed 
books,  the  date,  place,  printer,  and  preface,  often  enable 
us  easily  to  distinguish  the  successive  variations,  which 
are  occasionally  so  great  as  to  render  the  various  edi- 


SEC.  4.]  MATERIAL  CORRUPTIONS.  233 

tions,  in  reality,  different  works.  But  we  seldom  have 
such  aids  in  the  case  of  manuscripts.  Yet  the  circum- 
stances and  habits  of  ancient  writers  were  such,  that  dif- 
ferent editions -of  a  work  can  rarely  be  presumed  to  have 
emanated  from  the  author,  while  unequivocal  proof  of 
such  a  thing  can  hardly  be  found ;  and  consequently  we 
may  presume  that  there  is  only  one  genuine  version. 

It  is  sometimes  doubtful  whether  a  work  is  an  origin- 
al .composition,  or  only  an  abridgement,  executed  prob- 
ably by  some  other  person-  than  the  author.  Here  we 
must  generally  rely  on  external  evidence,  as  the  question 
usually  arises  only  where  the  original  has  perished.  In 
other  cases,  differences  of  style  and  expression  may  clear- 
ly indicate  that  the  abridgement  was  not  made  by  the 
original  author. 

In  investigating  the  character  of  a  particular  copy,  it 
is  frequently  important  to  know  the  age^  or  country  in 
which  it  was  written  or  printed.  The  former  can  gener- 
ally be  determined,  to  a  great  degree  of  accuracy,  by  ob- 
serving the  language,  orthography,  divisions  of  lines  and 
words,  punctuation,  contractions,  abbreviations  and  dia- 
critical marks,  embellishments  and  flourishes,  material, 
and  ink.  These  all  varied  so  much,  from  age  to  age, 
that  a  careful  examination  of  them  will  generally  enable 
a  person  who  has  studied  the  subject,  to  determine  the 
age  of  a  manuscript  within  half  a  century.  The  country 
in  which  a  manuscript  was  written,  can  frequently  be  as- 
certained by  the  same  means,  since  it  is  found  that  dif- 
ferent countries  adopted  different  forms  and  methods. 

The  characteristics  of  the  several  ages  and  countries 
are  ascertained  from  writings  of  which  the  origin  is 
known,  either  from  their  nature  or  from  immediate  testi- 
mony. To  the  former  class  belong  original  deeds,  char- 
ters, letters,  proclamations  and  public  records.  Some  of 
these,  however,  are  counterfeit ;  and,  therefore,  care  is 
required  to  distinguish  them  from  the  genuine. 

Printed  works  generally  indicate  the  place,  printer,  and 
year,  on  the  title-page  and  its  reverse,  or  at  the  end.  But 
some  books  lack  these,  or  give  fictitious  ones,  in  which 
case  recourse  must  be  had  to  the  preceding  methods. 
The  character  of  the  materials,  and  the  appearance  of 
the  type,  ink,  and  binding,  often  indicate  their  age  and 
origin,  while  the  printer  is  frequently  known  from  his  col- 
ophon, or  peculiar  device,  at  the  end  of  the  volume,  or 
in  the  title-page. 


2-34  EVIDENCE.  [CHAP.  XII. 

III.  A  third  difficulty,  which  frequently  attends  writ- 
ten testimony  is,  that  there  are  various  readings,  or  slight- 
ly different  versions  of  it.  These  arose  from  various 
causes.  The  old  copyists,  who  supplied  the  place  of 
printing,  before  the  use  of  that  art  became  general,  did 
not  always  detect  or  correct  the  accidental  mistakes 
which  occurred  in  their  manuscripts,  since  this  both  im- 
posed labor  and  disfigured  their  appearance.  Other  er- 
rors arose  from  the  same  sources  as  spurious  passages, 
and  some  proceeded  from  the-  marginal  glosses  of  preced- 
ing copyists  or  readers  being  mistaken  for  omissions,  and 
consequently  inserted  in  the  text.  Others  were  caused 
by  substituting  a  phrase  which  was  better  known  for  one 
which  was  beconiing  obsolete  or  belonged  to  another  di- 
alect. Many  arose  from  misreading  or  forgetting  the 
original,  and  then  substituting  a  similar  but  different  ex- 
pression. 

It  is  also  very  possible  that  there  may  be  several  gen- 
uine readings  of  a  passage,  just  as  there  may  different 
genuine  editions ;  and  the  remarks  already  made  regard- 
ing the  latter,  apply  equally  to  the  former.  In  modern 
authors,  they  are  of  common  occurrence,  and  easily  as- 
certained :  but  the  case  is  frequently  otherwise  with  old- 
er compositions,  in  which  we  have  rarely  any  proof  that 
more  than  one  reading  ever  proceeded  from  the  author. 

Printed  copies  are  generally  more  accurate  than  an- 
cient manuscripts,  because  various  errors  are  corrected, 
by  means  of  proof  sheets,  before  the  impression  is  struck 
off;  and  they  are  also  less  subject  to  omissions  or  addi- 
tions, either  accidental  or  designed,  while  they  render  im- 
practicable any  subsequent  alterations  of  all  the  copies 
of  an  edition ;  and  although  printed  copies  are  by  no 
means  exempt  from  errors,  yet  the  critical  comparison 
of  good  manuscripts  or  copies,  and  more  care  in  printing, 
tend  to  produce  more  and  more  accurate  versions,  till  a 
text  is  formed  free  from  any  serious  error. 

Although  a  single  copy  or  impression  lasts  only  for  a 
definite  period,*yet  the  arts  of  printing,  photography,  en- 
graving and  stereotyping  enable  us  to  multiply  accurate 
copies,  or  facsimiles  of  manuscripts  indefinitely,  so  that 
the  testimony  can  be  preserved  unchanged,  to  the  remot- 
est times. 

The  rules  already  given,  regarding  the  genuineness  of 
a  composition,  are  equally  applicable  to  this  subject ;  and 


SEC.  4.]  VARIOUS  READINGS.  235 

the  following  are  the  principal  additional  rules,  for  ascer- 
taining the  true  reading : 

1.  The  oldest  manuscript  of  an  ancient  author  is  to  be 
preferred  when  other  things  are  the  same.    But  the  rule 
does  not  apply  where  a  later  manuscript  has  been  more 
directly  derived  from  the  original,  or  where  a  manuscript 
is  found  to  have  been  either  carelessly  written  at  first,  or 
afterwards  corrupted. 

2.  Where  several  genuine  readings  exist,  the  most  re- 
cent is  to  be  deemed  the  best.     This  rule  assumes  that 
the  last  reading  expresses  the  author's   most  mature 
thoughts ;  and,  therefore,  where  the  case  is  otherwise,  it 
does  not  apply,  as  if  a  man  in  his  dotage  or  in  a  fit  of  in- 
sanity should  undertake  to  alter  the  productions  of  his 
better  days,  or  should  wilfully  corrupt  them,  from  some 
bad  motive. 

3.  The  reading  of  the  great  majority  of  copies  is  to  be 
preferred,  unless  there  is  conclusive  proof  that  it  is  erro- 
neous. 

4.  A  reading  which  is  conformable  to  the  known  views, 
sentiments  or  style  of  the  author,  is  preferable  to  one 
which  is  not,  unless  the  former  is  demonstrably  erro- 
neous. 

5.  A  reading  which  gives  a  good  or  correct  sense,  is 
better  than  one  which  gives  either  nonsense  or  an  erro- 
neous statement.     This  rule  applies  only  to  the  testimo- 
nies of  persons  who  are  not  destitute  of  sense  or  honesty. 

6.  A  reading  which  violates  the  idiom  or  grammar  of 
the  language,  is  to  be  rejected  for  one  which  does  not. 
It  is  assumed  that  the  author  wrote  with  care,  and  knew 
the  language :  else  this  rule  does  not  apply. 

V.  Of  two  admissible  readings,  that  which  was  most 
liable  to  be  changed,  is  to  be  preferred.  Thus,  a  reading 
at  variance  with  the  opinion  of  the  copyists,  or  conflict- 
ing with  some  strong  prejudice  of  the  party  addressed,  is 
preferable  to  one  which  conforms  to  it. 

8.  Of  several  readings  otherwise  equally  probable,  that 
which  best  agrees  with  the  context,  is  to  be  preferred. 

9.  A  reading  which  is  a  manifest  blunder  or  corrup- 
tion, is  to  be  disregarded. 

10.  The  reading  of  a  good  is.  preferable  to  that  of  a 
bad  copy,  where  there  is  no  proof  to  the  contrary. 

11.  A  good  copy  is  known  by  its  general  accuracy, 
and  its  containing  few  manifest  errors,  or  by  the  testi- 


236  EVIDENCE.  [CHAP.  XIL 

mony  of  persons  who  knew  the  original,  or  copies  direct- 
ly and  carefully  made  from  it. 

12.  An  inaccurate  copy  is  known  by  its  abounding 
with  unquestionable   errors,  its  being  evidently  made 
without  care,  or  by  the  testimony  of  those  who  know 
its  real  character. 

13.  A  printed  copy  of  which  the  author  corrected  the 
proof  sheets,  is  good  :  but  if  he  did  so  carelessly,  a  copy 
diligently  corrected  from  his  original  manuscript,  may 
be  better. 

14.  Where  all  the  copies  of  an  early  translation  show 
no  variations  of  a  passage,  its  reading  is  equivalent  to  a 
copy  of  the  age  in  which  it  was  made.     The  rule  assumes 
that  there  is  no  room  to  doubt  the  genuineness  of  the 
passage,  or  the  mode  in  which  the  translator  read  his 
original :  otherwise  it  is  inapplicable. 

15.  The  preceding  rule  is  applicable  to  quotations,  if 
not  made  from  memory.     It  is  observable,  however,  that 
quotations  are  often  made  from  memory ;  and,  in  such 
cases,  they  are  of  little  use  in  ascertaining  the  true  read- 
ing- 

16.  In  modern  compositions,  the  true  reading  may  fre- 
quently be  ascertained  by  referring  to  the  original  man- 
uscript, or  to  some  person  who  directly  knows  that  read- 
ing.    But  we  must  beware  of  mistaking  an  inaccurate 
copy,  or  the  rough  draught,  for  the  original  manuscript. 
The  true  original  is  the  finished  composition,  and  not 
the  first  copy. 

17.  Conjectural  emendations  are  allowable  only  where 
the  text  is  certainly  corrupt,  while  the  proposed  emen- 
dation harmonizes  with  the  context,  and  has  every  appear- 
ance of  having  been  the  original  reading.     The  obscurity 
of  a  passage  does  not  justify  the  admission  of  such  emen- 
dations, since  it  may  arise  from  our  ignorance,  and  disap- 
pear after  we  have  become  better  acquainted  with  the 
language  and  the  subject  of  discourse.     Hence  the  text 
might  be  corrupted,  instead  of  being  improved,  by  a  too 
ready  admission  of  emendations  of  this  kind. 

Most  various  readings  are  of  little  importance,  because 
they  do  not  materially  affect  the  sense.  But  some  of 
them  are  serious ;  and  these  abound  in  works  which  have 
been  copied  very  carelessly. 

IV.  The  fourth  .difficulty  which  sometimes  attends 
written  testimony,  is,  that  we  are  left  to  doubt  whether 


SEC.  4.]  FICTION.  237 

the  narrative  is  authentic  or  fictitious.  Here  we  must 
examine  the  external  and  internal  evidences,  as  when  we 
are  investigating  the  authorship,  the  determination  of 
which  will  generally  remove  this  difficulty  also. 

The  character  of  the  composition  may  possibly  be 
learned  readily  from  testimony.  Thus  we  learn  that 
"The  Life  and  Surprising  Adventures  of  Robinson  Cru- 
soe" is  a  fictitious  autobiography,  written  by  Daniel  De- 
foe, though  partly  based  on  the  real  adventures  of  Alex- 
ander Selkirk.  So  we  learn  that  Julius  Caesar's  "  Com- 
mentaries on  the  Gallic  War"  is  an  authentic  narrative, 
regarding  real  personages  and  events. 

Fiction  generally  betrays  its  character,  either  by  its 
absurdity  or  its  inconsistency  with  what  we  know  from 
other  reliable  sources.  If  the  writer  gives  dates,  and 
the  names  of  persons  and  places,  we  may  compare  his 
statements  with  what  is  otherwise  known  regarding 
them,  when  we  shall  generally  ascertain  the  character  of 
the  narrative,  with  little  difficulty.  If  he  gives  only  fic- 
titious names,  his  testimony  is  not  entitled  to  belief,  un- 
less we  possess  other  conclusive  evidence  of  its  authen- 
ticity. 

The  character  of  a  narrative  is  generally  unfolded  by 
subsequent  researches  or  discoveries,  regarding  the  sub- 
jects of  which  it  treats,  as  in  other  cases  of  testimony. 
Thus,  we  learn  that  the  accounts  which  several  ancient 
authors  give  of  the  Pygmies,  though  long  believed,  are 
quite  fabulous,  while,  on  the  other  hand,  numerous  state- 
ments of  ancient  historians,  which  were  long  regarded 
as  fictitious,  have  been  confirmed  by  recent  discoveries. 

This  section  is  mostly  applicable  to  all  kinds  of  written 
composition,  as  well  as  to  testimony  in  its  narrower  sig- 
nification, or  that  which  regards  only  the  witness's  im- 
mediate comprehension,  since  the  general  modes  of  ascer- 
taining the  origin  and  character  of  writings  are  the  same, 
to  whatever  class  they  belong:  and,  so  far  as  concerns 
our  present  purpose,  everything  which  a  person  asserts, 
may  be  termed  his  testimony. 


238  CLASSIFICATION.  [CHAP.  XIII. 


CHAPTER  XIII. 

OF     CLASSIFICATION. 

§  1.  NATURE  AND  USES  OF  CLASSIFICATION. — Definition  of  Classifi- 
cation.— Two  kinds  of  it. — Naming  essential. — How  distinguished 
from  Generalization. — Objects  susceptible  of  Physical  Classifica- 
tion.— Why  this  is  preceded  by  the  Mental  Process. — Five  main 
Objects  of  the  latter,  with  Observations. — Division. — Important 
Distinction. 

Classification  is,  arranging  together  such  things  as 
resemble  each  other,  and  separating  them  from  such  as 
are  unlike :  and  it  is  either  mental  Q^pkyaioal.  The  for- 
mer consists  in  determining  what  things  are  alike  in  some 
respects,  and  unlike  others  in  the  same  respects,  and  dis- 
tinguishing them  by  a  suitable  name.  The  latter  con- 
sists in  actually  arranging  or  assorting  together  physical 
objects,  which  have  been  formed  into  classes  by  the  men- 
tal process.  If  a  man  has  a  lot  of  shells,  he  may  first 
determine  how  many  kinds  there  are,  with  the  peculiar- 
ities of  each,  and  give  every  class  a  name.  This  is  the 
mental  classification.  When  he  places  together  all  the 
shells  that  belong  to  the  same  class,  and  removes  those 
which  do  not,  this  is  physical  classification. 

Naming  the  various  classes  is  an  essential  part  of  clas- 
sification :  for  it  is  requisite  to  a  proper  remembrance  or 
description  of  their  several  peculiarities.  Hence  a  good 
system  of  nomenclature  greatly  facilitates  induction ; 
and  it  is  also  requisite  in  order  to  secure  the  chief  ob- 
jects of  classification. 

Classification  differs  from  generalization  in  comparing 
like  with  unlike,  separating  the  two,-  and  distinguishing, 
every  class  by  a  suitable  name.  We  might  generalize 
if  we  had  only  one  species  before  us :  but  classification 
requires  us  to  compare  individuals  of  several  species. 
Generalization  necessarily  precedes  classification,  because 
we  cannot  classify  objects  till  we  have  first  ascertained 
their  common  resemblances,  as  well  as  their  common 
differences. 

Physical  or  material  objects  alone  are  susceptible  of  a 
physical  classification  :  for,  although  we  may  classify  men- 


SEC.  1.]  ITS  USES.  239 

.tal  phenomena,  or  the  peculiarities  of  individual  charac- 
ter, it  is  impracticable  to  arrange  such  things  together. 

As  physical  classification  is  only  an  actual  assorting 
of  things,  according  to  the  dictates  of  the  mental  process, 
the  latter  must  always  precede  it. 

The  main  objects  of  mental  classification  are  the  five 
following. 

1.  To  aid  the  Memory.    The  simple  objects  in  nature 
are  so  numerous,  and  frequently  so  unlike  each  other, 
that  we  cannot  remember  the  properties  of  any  great 
portion  of  them,  without  arranging  them  in  such  a  way 
that  we  can  consider  those  which  are  alike  consecutively, 
and  thus  obviate  the  necessity  of  running  continually 
from  one  object  to  another  extremely  unlike  it.     This 
can  evidently  be  effected  only  by  means  of  classification. 

2.  To  facilitate  induction.    It  is  only  after  those  things 
which  are  obviously  alike  have  been  arranged  together, 
and  separated  from  those  which  are  unlike,  that  we  can 
advantageously  proceed  to  investigate  their  general  prop- 
erties.    We  first  ascertain  individual  facts,  and  then  ex- 
tend our  observations,  till  we  establish  some  kind  of  gen- 
eralization.    This  is  followed  by  a  corresponding  classi- 
fication, which  is  usually  succeeded  by  an  induction :  and 
the  latter  often  leads  to  an  improved  classification,  which 
may  prepare  the  w^ay  for  a  more  extensive  induction. 

3.  To  assist  us  in  determining  the  character  of  an  in- 
dividual.    By  simply  ascertaining  that  it  exhibits  some 
characteristic  mark  of  a  class,  we  know  at  once  that  it 
belongs  to  that  class,  and  possesses  all  its  peculiarities, 
a  thing  which  might  otherwise  be  very  difficult,  or  even 
impracticable.     Thus,  a  zoologist  can  ascertain  the  gen- 
eral structure  and  habits  of  a  quadruped  from  simply 
inspecting  the  bones  of  the  foreleg. 

4.  To  prepare  for  physical  arrangement.     Where  this 
preliminary  process  does  not  receive  due  attention,  much 
confusion  and  loss  of  time  are  apt  to  result,  because  a 
thing  cannot  be  found  when  it  is  wanted,  or  it  cannot  be 
ascertained  what  is  wanted   and  what  is   superfluous. 
Proper  physical  arrangement  of  tools,  apparatus  and  ma- 
terials is  generally  requisite  to  success  in  the  arts,  and 
also  in  many  scientific  investigations. 

5.  To  facilitate  the  communication  of  knowledge  to  oth- 
ers.    This  is  sometimes  termed  division /  and  it  belongs 
to  Rhetoric,  rather  than  to  Logic.     Its  leading  principle 


240  CLASSIFICATION.  [CHAP.  XIII. 

is,  that  things  should  be  so  arranged  as  to  render  an  un- 
derstanding of  the  subject  as  easy,  and  the  proofs  as  clear 
and  conclusive,  as  possible.  The  principle  that  things 
the  most  like  should  be  classed  together,  which  is  gener- 
ally supreme  in  Logic,  should  here  be  subordinated  to 
the  leading  principle ;  and  many  didactic  treatises  have 
been  seriously  injured  by  the  author's  confounding  rhe- 
torical with  logical  classification,  two  things  which  often 
differ  widely. 

§  2.  PRINCIPLES  AND  METHODS  OF  CLASSIFICATION. — General  Prin- 
ciple of  Classification. — Why  there  are  many  Special  Principles. — 
Primary  and  Subordinate  Principles. — What  determines  the  form- 
er.— Seven  Rules  of  Classification. — Essential  and  Non-essential 
Properties. — Classification  of  Organic  Bodies. — Limits  of  Species. 
— Method  of  forming  Genera,  Families,  Orders,  and  Classes. — Its 
Advantages. — Modes  of  naming  Organic  Divisions. — Application 
and  Improvement  of  Principles. — Influence  of  Prejudices,  and  how 
avoidable. 

Similarity  and  diversity  form  the  bases  of  all  classifi- 
cation, the  general  principle  being,  that  things  which  are 
similar  are  to  be  classed  together p,  and  separated  from 
such  as  differ.  But  as  things  are  like  and  unlike  each 
other  in  various  respects,  there  are  many  special  princi- 
ples of  classification. 

The  primary  principle  of  a  classification  is,  that  ac- 
cording to  which  things  are  grouped  in  the  first  instance, 
without  allowing  any  other  to  interfere.  A  subordinate 
principle  is,  that  according  to  which  these  groups  are 
subdivided. 

The  particular  object  of  the  arrangement  determines 
which  of  several  possible  primary  principles  is  to  be 
adopted.  The  tax-gatherer  classes  men  according  to 
their  residences  and  amount  of  property — the  physiolo- 
gist, according  to  their  corporal  peculiarities — and  the 
moralist,  according  to  their  ethical  principles  and  con- 
duct. 

The  following  are  the  principal  rules  of  classification : 

1.  Every  classification  should  be  made  according  to  a 
certain  principle,  with  which  no  other  should  interfere. 
This  rule  is  evidently  requisite  to  prevent  confusion.  If 
a  librarian,  in  first  classifying  his  books,  should  at  one 
time  arrange  them  according  to  their  subjects,  and  at  an- 
other, according  to  the  language  in  which  they  are  writ- 
ten, volumes  which  treated  of  different  subjects  would 


SEC.  2.]  PRINCIPAL  RULES.  241 

stand  together  in  one  place,  and  some  which  were  com- 
posed in  different  languages  would  be  found  in  juxtapo- 
sition elsewhere,  so  that  both  principles  would*  be  vio- 
lated. 

2.  The  principle  should  be  definite,  and  not  difficult  of 
application.     Otherv/ise  it  would  be  doubtful  in  which 
class  a  certain  thing  should  be  placed,  and  it  might  hap- 
pen to  belong  equally  to  two  co-ordinate  classes.     The 
principle  that  all  those  plants  are  to  be  classed  together 
which  are  essentially  alike,  although  good  as  a  general 
rule,  is  too  indefinite  as  a  general  principle,  because  it 
leaves  doubtful  what  essential  likeness  is. 

3.  The  principle  should  apply  equally  to  all  the  things 
to  l)e  classified.     Otherwise  some  part  may  be  entirely 
omitted  in  the  classification.     The  primary  principle  that 
all  animals  are  to  be  classed  according  to  the  structure 
of  the  nervous  system,  is  objectionable,  because  many 
animals  have  no  such  system. 

4.  The  principle  should  bring  together  those  things 
which  our  object  requires  us  to  unite,  and  separate  them 
from  all  others:  else  the  classification  would  not  answer 
the  purpose.    The  principle  that  animals  should  be  class- 
ed according  to  their  apparent  affinities,  is  bad,  because 
these  often  differ  widely  from  the  real  affinities, 

5.  We  should  commence  with  the  highest,  and  proceed 
gradually  to  the  lowest  divisions  of  our  subject.     As  the 
former  are  separated  by  the  greatest  and  most  striking 
differences,  they  are  generally  the  most  easily  made :  and 
it  is  necessary  to  survey  all  that  is  to  be  classified,  and 
form  the  higher  divisions,  before  we  can  rightly  fix  the 
limits  of  the  lower.     Thus,  in  classifying  all  animals,  we 
should  begin  with  what  are  termed  the  sub-kingdoms, 
then  proceed  to  the  classes,  thence  to  the  orders,  thence 
to  the  families  and  genera,  and,  lastly,  to  the  species : 
otherwise  it  would  be  impossible  to  effect  an  harmonious 
and  satisfactory  classification. 

6.  In  all  the  sciences  which  treat  of  organic  beings,  as 
such,  those  things  are  generally  to  be  classed  together 
which  are  most  like,  or  resemble  each  other  in  the  great- 
est number  of  particulars.     For  the  properties  of  such 
bodies  are  best  understood  and  remembered,  when  ev- 
erything is  arranged  beside  that  which  it  most  resembles, 
because  this  renders  the  points  of  similarity  most  appa- 
rent, and  the  mind  naturally  associates  things  according 

L 


242  CLASSIFICATION.  [CHAP.  XIII. 

to  their  similarities.  Hence  plants  should  not  be  classed 
solely  according  to  the  structure  of  the  organs  of  fructi- 
fication, because  many  plants  have  no  such  organs,  and, 
in  the  case  of  others,  the  general  structure  is  frequently 
unconformable  to  that  of  those  organs. 

Essential  and  non-essential  peculiarites  should  be  dis- 
tinguished. The  former  are  those  which  determine  a 
thing  to  be  what  it  is,  and  which  cannot  be  altered  with- 
out subjecting  it  to  a  complete  structural  change:  the 
latter  are  such  as  may  alter  without  producing  any  struc- 
tural change.  In  animals,  the  structure  of  the  organs  of 
nutrition  and  motion  are  essential  properties,  while  the 
size,  the  color,  and  the  appearance  of  the  covering,  are 
non-essential.  Thus,  a  dog  may  be  larger  or  smaller, 
black  or  white,  straight-haired,  curly-haired,  or  wholly 
hairless:  but  he  could  not  have  teeth  and  feet  like  a 
sheep's  without  ceasing  to  be  a  dog.  This  distinction 
leads  to  the  following  principle,  which  qualifies  the  sixth. 

7.  Organic  beings  which  resemble  each  other  in  essen- 
tial properties  are  to  be  classed  together,  although  they 
may  differ  in  others.  Grayhounds  must  be  classed  with 
dogs,  and  not  with  hyenas,  because  they  exhibit  the  es- 
sential peculiarities  of  dogs,  although,  in  several  respects, 
they  resemble  hyaBnas  more  than  they  do  poodles. 

In  classifying  organic  beings,  all  those  individuals  are 
considered  to  be  of  the  same  species  which  differ  only  in 
such  peculiarities  as  are  found  to  vary  in  individuals 
known  to  have  sprung  from  the  same  parentage;  and 
where  two  individuals  exhibit  differences  that  are  con- 
stant, and  resist  change,  in  those  which  have  a  common 
origin,  under  every  variety  of  external  circumstances, 
they  are  considered  of  different  species. 

In  forming  species  into  genera,  a  different  course  must 
be  adopted :  for  the  latter,  unlike  the  former,  are  marked 
by  no  definite  natural  boundaries.  The  following  method 
appears  to  be  the  best  which  has  been  hitherto  proposed. 

A  particular  species  which  exhibits,  in  a  marked  de- 
gree, the  chief  peculiarities  common  to  several  very  simi- 
lar species,  is  taken  as  the  type,  or  best  representative, 
of  the  whole  group ;  and  all  those  species  which  resem- 
ble this  type  more  than  they  do  any  kindred  one,  are 
classified  with  it,  as  being  of  the  same  genus. 

The  number  of  types  to  be  adopted,  depends  on  the 
number  of  groups  of  species  which  exhibit  such  differ- 


SEC.  2.]  ORGANIC  BEINGS.  243 

cnces  that  it  would  not  comport  with  the  object  of  the 
classification  to  arrange  them  in  the  same  genus. 

The  higher  divisions  of  families,  orders  and  classes 
may  be  formed  in  the  same  way,  by  adopting  one  of  the 
subordinate  divisions  as  a  type. 

This  method  facilitates  both  classification  and  study. 
For  we  have  only  to  compare  a  new  or  unclassed  species 
with  the  types  which  it  closely  resembles,  in  order  to  de- 
termine its  proper  place,  while  the  type  gives  the  stu- 
dent a  good  view  of  the  characteristics  of  the  group,  and 
the  peculiarities  of  every  species  are  easily  acquired  aft- 
erwards. So,  the  typical  genus  may  represent  its  order, 
and  the  typical  order,  its  class. 

A  genus  is  distinguished  by  a  generic  name,  and  this 
is  prefixed  to  a  specific  Designation,  to  form  that  of  the 
species,  which  thus  indicates  both  the  genus  and  the  spe- 
cies. Thus,  bos  is  the  generic  name  of  the  ox  tribe ;  JBos 
taurus  is  the  common  ox,  and  Bos  Americanus,  the  Amer- 
ican ox,  frequently  miscalled  the  buffalo.  So,  Quercus  is 
the  generic  name  of  the  oaks :  Quercus  pedunculata  is 
the  European  white  oak,  and  Quercus  alba,  the  American 
white  oak. 

The  orders  are  named  from  some  striking  peculiarity 
or  some  well-known  genus.  Thus,  Muminantia  (cud- 
chewers)  is  the  name  of  that  large  and  important  order 
of  mammals  which  possesses  four  stomachs  and  rumi- 
nates ;  and  the  rose  gives  name  to  the  extensive  vegeta- 
ble order  of  the  Rosacece,  including  the  rose,  apple,  pear, 
quince,  plnm,  peach,  almond,  nectarine,  cherry,  black- 
berry, raspberry,  and  strawberry,  which  are  all  charac- 
terized by  alternate  leaves,  several  sepals,  regular  petals, 
distinct  stamens,  and  separate  carpels. 

Families  or  sub-orders  are  generally  named  by  modify- 
ing the  name  of  some  well-known  genus.  Thus,  Canidce 
denotes  the  canine  family,  from  canis,  the  term  for  the 
dog  genus  ;  and  Bovidce  expresses  the  cattle  family,  from 
bos,  the  name  of  the  ox  genus. 

The  classes,  which  are  comparatively  few  in  number, 
are  designated  either  from  one  of  their  chief  characteris- 
tics or  from  their  common  collective  name.  Thus,  the 
class  Mammalia  is  named  from  the  peculiarity  of  suck- 
ling their  young,  and  the  birds  are  termed  Aves,  which 
is  only  their  ordinary  Latin  name.  So,  in  Botany,  one 
great  class  is  termed  Exogens  (out-growers),  from  their 


244  CLASSIFICATION.  [CHAP.  XIII. 

growth  being  formed  by  new  layers  around  that  of  the 
preceding  season,  such  as  the  common  forest  trees  of 
temperate  regions ;  and  another  is  termed  Endogens  (in- 
growers),  from  the  new  growth  being  deposited  among 
and  within  the  old,  such  as  the  grasses,  lilies,  and 
palms.  (17) 

In  effecting  a  classification  of  many  objects  and  kinds, 
we  must  first  lay  down  proper  primary  and  subordinate 
principles,  then  arrange  the  objects  according  to  the  dic- 
tates of  our  primary  principle,  then  subdivide  every  di- 
vision, according  to  the  requirements  of  our  most  gener- 
al subordinate  principle,  and  so  on,  till  we  come  to  the 
lowest  subdivision. 

When  we  have  to  class  a  newly  discovered  or  invent- 
ed object  in  its  proper  place,  we  must  ascertain  the  di- 
vision to  which  it  properly  belongs,  from  its  classic,  or- 
deric,  generic,  and  specific  characteristics,  or  those  which 
distinguish  the  class,  order,  genus,  or  species  from  its  co- 
ordinate divisions.  We  begin  with  those  of  the  highest 
division  and  proceed  gradually  to  those  of  the  lowest, 
arrange  the  object  accordingly,  and  distinguish  it  by  a 
suitable  name.  Thus,  if  we  had  just  discovered  the  musk 
ox  of  Arctic  America,  the  first  glance  would  show  that  it 
is  of  the  mammal  class,  while  its  horns  and  teeth  charac- 
terized it  as  of  the  ruminant  order:  but  its  generic  char- 
acter is  not  so  easily  determined.  Its  horns  and  general 
character  indicate  that  it  is  an  ox,  while  its  long,  woolly 
hair,  its  short  legs,  its  nose  and  its  face,  ally  it  to  the 
sheep  .tribe.  Hence  it  is  classed  as  an  intermediate  ge- 
nus, under  the  term  Ovibos  (sheep-ox),  while  the  species 
is  designated  Moscliatus  (musky),  from  its  rank  musky 
smell. 

In  effecting  a  physical  classification  of  objects,  we  first 
select  and  arrange  together  those  which  exhibit  the  char- 
acteristic marks  of  the  various  divisions  immediately  be- 
low that  to  which  they  all  belong,  and  then  subdivide 
the  groups  thus  formed,  by  placing  together,  apart  from 
the  rest,  all  those  objects  which  possess  the  characteris- 
tics of  the  various  groups  of  the  next  lower  subdivision, 
and  so  on,  till  we  arrive  at  the  lowest. 

Wherever  it  is  found  that  our  principles  are  objection- 
able, because  they  fail  to  effect  the  desired  result,  we 
should  modify  or  alter  them,  so  as  to  remove  the  difficul- 
ty* by  which  means  we  may  gradually  arrive  at  perfect 


SEC.  2.]  PREJUDICES.  245 

principles.  Thus,  if  a  librarian  attempts  to  arrange  all 
his  books  on  the  primary  principle  that  those  treating  of 
the  various  subjects  were  to  be  separated,  he  would  soon 
find  that  his  principle  is  objectionable,  because  many 
books  treat  of  different  subjects.  This  would  lead  him 
to  the  better  primary  principle,  that  books  which  treated 
of  several  distinct  subjects,  were  to  be  separated  from 
such  as  treated  of  only  one  subject ;  and  then  he  could 
properly  apply  his  original  principle  to  the  latter. 

Prejudices  may  injuriously  affect  this  subject,  as  well 
as  every  other,  because  we  are  strongly  tempted  to  place 
a  favorite  individual,  and  especially  ourselves,  in  a  class 
better  than  that  to  which  he  really  belongs,  and  to  re- 
verse this  error,  in  the  case  of  a  being  that  we  dislike. 
The  proper  course  is,  to  ascertain  the  individual's  real 
characteristics,  and  then  set  him  down  in  that  class  to 
which  he  is  unequivocally  attributed  by  the  proper  prin- 
ciple. 


246 


CLASSIFICATION. 


[ClIAP.  XIV. 


2.  All  the  intel- 
lectual  fac- 


by  signs  and 
symbols,       ) 


CHAPTER  XIV. 

TABULAR  VIEW   OF   THE   MEANS   OF   ACQUIRING  KNOWL- 
EDGE. 

I.  Necessary  and  Universal  Truths  are  learned  by 

((1.)  Truisms. 

1.  Direct  Intuition,     8')  Self-evident  properties i  of  Time  and  Space, 
including  •{  gO  Abstract  Quantity. 

1(4.)  Substantial  Beings. 

[  (6*5  Relations  of  Things. 

f  (1.)  The  necessary  properties  of  Space  and 

Time,  which  are  not  self-evident. 
(2.)  The  necessary  properties  of  Abstract 
Quantity,  which  are  not  self-evident. 
(3.)  The  necessary  properties  of  Substantial 

Beings,  which  are  not  self-evident. 
(4.)  The  necessary  properties  or  Relations 
of  Things,  which  are  not  self-evident. 

II.  Particular  Contingent  Truths  are  known  by 

f  (1.)  Perceptions. 
1.  Direct  Comprehension,  including  1  (2.)  Sensations. 

our  present  j  (3.)  Ideas  and  phantasms. 

(  (4.)  Emotions  and  desires. 
(1.)  Our  own  existence. 
(2.)  That  of  other  substantial 

beings  around  us. 
(3.)  The  obvious  properties  of 

us  and  them. 

(4.)  Our  own  past  experience. 
(5.)  That  of  others,  including 
History  and  Biography. 

III.  General  Contingent  Truths  are  known  by 

1.  Comprehension  and  Abstraction,  whence  we  learn  empiricisms  re- 

garding the  present. 

2.  Comprehension,  Abstraction,  and  Memory,  aided  by  audible  and 

visible  signs,  including  Testimony,  whence  we  know  empiricisms 
regarding  the  past. 

3.  Comprehension,  Abstraction,  Memory,  and  Intuition,  generally  aid- 

ed by  signs  and  apparatus,  whence  we  learn-  obvious  inductions 
regarding  the  past,  present,  and  future. 

4.  All  the  intellectual  faculties,  aided  as  in  the  preceding  case,  whence 

we  learn  recondite  inductions  and  inventive  truths. 

IV.  Hypothetical  Truths  and  Probabilities  are  learn- 
ed by  the  same  means  as  the  third  class. 


2.  Comprehension,  Intui- 
tion, and  Memory, 
often  aided  by  Testi- 
mony and  numerous 
external  appliances, 


whence 
we  know 


PART  III, 

OF   FALLACIES. 


CHAPTER  XV. 

NATURE   AND  CLASSIFICATION    OF   FALLACIES. 

§  1.  NATURE  OF  FALLACIES. — Definition  and  Operation  of  Fallacies. 
— Why  they  frequently  produce  Belief. — Their  Number. — Two 
Evils  resulting  from  Fallacies. 

A.  fallacy  is,  any  thought,  expression,  or  argument, 
which  tends  to  produce  erroneous  belief.  It  has  always 
some  semblance  of  proving  a  certain  conclusion,  with- 
out .which  it  could  have  no  such  tendency ;  and  we  are 
frequently  liable  to  adopt  the  error,  without  ever  sus- 
pecting its  existence.  When  a  fallacy  is  clearly  exposed 
or  understood,  its  worthlessness  as  a  proof  appears  so 
glaring,  that  we  are  apt  to  think  it  could  never  impose 
on  anybody ;  yet,  when  presented  in  the  disguised  and 
indirect  form  in  which  fallacies  usually  come  before  the 
mind,  it  often  produces  conviction,  especially  when  fa- 
•vored  by  prejudices ;  and  it  cannot  sometimes  be  detect- 
ed without  close  attention  and  great  care. 

The  difficulty  is  frequently  increased,  and  the  recep- 
tion of  the  fallacy  facilitated,  by  the  argument's  contain- 
ing a  combination  of  fallacies,  in  which  one  conceals,  and 
consequently  strengthens,  another,  and  its  being  believed 
by  the  party  who  propounded  it,  and  who  is  consequent- 
ly sincere  in  his  advocacy  of  it.  We  are  also  liable  to 
overlook  fallacies  which  originate  wholly  with  ourselves, 
because  we  do  not  suspect  their  existence,  and  are  un- 
willing to  believe  that  we  have  been  misled.  Many  fal- 
lacies, again,  may  be  detected  by  a  very  brief  close  exam- 
ination of  them ;  yet,  owing  to  ignorance  of  their  nature, 
and  attention  not  being  called  to  the  defect,  no  such  ex- 
amination is  ever  made. 

Fallacies  have  no  definite  limit  as  to  number ;  and  they 
admit  of  endless  modifications  and  combinations,  so  that 
a  complete  enumeration  or  precise  definition  of  every  fal- 
lacy is  impracticable :  yet,  when  we  understand  the  na- 
ture and  operation  of  those  which  most  usually  occur, 
we  need  have  little  difficulty  in  detecting  all  others. 

Fallacies  hide  truth,  and  substitute  positive  error  in 
L  2 


250  NATURE  OF  FALLACIES.        [CHAP.  XV. 

its  place.  As  conscious  ignorance  is  preferable  to  delu- 
sion, it  were  better  not  to  engage  in  the  pursuit  of  truth 
at  all,  than  to  do  so,  and  fall  into  error,  which  not  only 
misleads  us  directly,  but  prevents  further  investigation, 
and  leads  to  the  rejection  of  every  incompatible  truth. 

§  2.  CLASSIFICATION  OF  FALLACIES. — Three  Classes  of  Fallacies. — 
(1)  Paralogisms. — (2)  Sophisms. — (3)  Aberrancies. — Universal  de- 
fect in  Fallacies. — Why  these  three  include  all  possible  Fallacies. 
— Their  independence  of  each  other. — What  invalidates  an  Argu- 
ment.— Practical  Application  and  Illustration. 

Fallacies  may  be  divided  into  the  three  following 
classes,  corresponding  to  the  three  parts  of  a  syllogism. 

1.  A  comprehension  exhibits  the  appearance  of  some- 
thing different  from  the  reality,  or  something  appears  to 
be  self-evident  or  known  by  satisfactory  proof  when  it 
is  neither ;  and  thus  we  are  led  to  infer  that  we  discern 
or  learn  something,  which,  in  truth,  we  do  not.     This 
class  we  term  paralogisms,  or  fallacies  of  primary  as- 
sumption.    A  paralogism  may,  therefore,  be  defined  a 
delusive  representation,  leading  directly  to  an  erroneous 
belief. 

2.  Something  is  inferred  from  a  premise  which  is  not, 
in  reality,  implied  in  it.     This  class  we  term  sophisms, 
or  fallacies  of  intermediate  reasoning.     A  sophism  may, 
therefore,  be  defined  a  syllogism  or  argument  in  which 
the  inference  or  conclusion  is  not  implied  in  the  premises. 

3.  The  actual  conclusion  is  not  the  proposition  which 
ought  to  have  been  proved,  but  one  essentially  different, 
which  forms  an  aberrancy,  or  fallacy  of  irrelevancy.     It 
is,  therefore,  an  argument  or  syllogism,  the  conclusion 
of  which  is  not  the  question,*  or  the  conclusion  which 
ought  to  have  been  proved,  but  one  essentially  different. 

There  is  a  false  inference  in  every  fallacy :  but  in  par- 
alogisms it  regards  primary  assumptions  —  in  sophisms, 
intermediate  reasoning — and  in  aberrancies,  a  final  con- 
clusion. Hence,  the  same  fallacy  whfth  is  a  sophism 
when  it  is  employed  to  prove  a  further  inference,  may 
become  a  paralogism  when  it  is  used  in  the  final  syllo- 
gism of  an  argument. 

The  above  three  classes  include  all  possible  fallacies ; 
for,  if  all  our  primary  assumptions  are  sound,  our  infer- 
ences from  them  legitimate,  and  our  final  conclusions  the 
very  things  to  be  established,  there  is  evidently  no  pos- 


SEC.  2.]          CLASSIFICATION  OF  FALLACIES.  251 

sibility  of  error.  Hence  all  fallacies  must  regard  our 
primary  assumptions,  our  reasonings  from  these,  or  our 
final  conclusions. 

Those  three  classes  of  fallacies  are  all  distinct  and  in- 
dependent. We  may  reason  correctly  from  unsound 
premises ;  or  we  may  reason  sophistically  from  unobjec- 
tionable premises ;  or  both  premises  and  reasoning  may 
avail  nothing,  since  they  are  beside  the  real  question : 
and  an  argument  is  rendered  worthless  by  involving  any 
one  of  those  fallacies.  One  material  defect  invalidates 
the  whole,  as  much  as  if  no  part  was  sound.  It  may  pos- 
sibly contain  two  or  three  kinds  of  fallacy :  yet,  in  exam- 
ining its  validity,  if  we  find  one  fallacy,  it  is  quite  un- 
necessary to  search  for  a  second. 

If  the  premises  require  proof,  and  none  is  given,  we 
need  not  search  to  see  whether  the  conclusion  is  implied 
in  them,  or  whether  it  is  relevant.  The  whole  is  like  a 
fabric  built  on  sand ;  and  it  is  not  stable,  however  strong 
the  superstructure.  It  is  not  requisite  to  show  that  the 
premises  are  false,  in  order  to  refute  an  argument  based 
on  them :  it  is  sufficient  to  show  that,  for  any  thing  which 
appears  to  the  contrary,  they  may  be  false.  If  they  arc 
doubtful,  an  argument  which,  in  order  to  be  valid,  re- 
quires that  they  must  be  known  truths,  is  as  worthless 
as  if  they  had  been  proved  to  be  false. 

If  it  appears  that  the  conclusion  is  not  implied  in  the 
premises,  it  is  unnecessary  to  test  their  soundness,  or  the 
relevancy  of  the  conclusion.  Here  the  fabric  has  no 
strength  in  itself;  and,  therefore,  the  firmness  of  its 
foundation  avails  nothing. 

If  the  conclusion  is  irrelevant,  all  that  precedes  is  tan- 
tamount to  nothing :  for  here  the  fabric  is  erected  on  a 
wrong  foundation ;  and,  therefore,  it  leaves  the  place 
where  it  ought  to  have  been  built  still  vacant. 


252  SOURCES  OF  FALLACIES.      [CiiAp.  XVI. 


CHAPTER,  XVI. 

SOURCES  OF  FALLACIES,  AND  MEANS  OF  GUARDING  AGAINST 
THEM. 

§  1.  SOURCES  OF  FALLACIES. — Twofold  Source  of  Fallacies. — Intrin- 
sic Sources. — Extrinsic  Sources. — Immediate  extrinsic  cause  of 
all  Fallacies. — How  it  operates. — Seven  causes  of  Inattention,  with 
Remarks. 

THE  sources  of  fallacies  are  either  intrinsic  or  extrinsic. 
The  former  lie  in  the  subject,  and  the  latter  in  the  inves- 
tigator. 

All  intrinsic  sources  of  fallacy  lie  in  one  thing's  re- 
sembling another  so  much  as  to  be  readily  mistaken  for 
it,  while  they  are  materially  different,  or  in  two  things 
differing  so  much  that  we  are  apt  to  think  they  differ 
altogether,  while  they  are  virtually  alike,  so  far  as  con- 
cerns the  matter  in  hand. 

The  intrinsic  source  of  paralogisms  is  found  in  a  delu- 
sive representation,  which  is  apt  to  lead  directly  to  the 
inference  that  we  know  or  learn  something  which,  in 
fact,  we  do  not. 

The  intrinsic  cause  of  sophisms  lies  in  one  thought  or 
expression's  being  so  like  another  as  to  be  readily  mis- 
taken for  it,  while  the  two  are  radically  different,  whence 
we  are  apt  to  infer  that  a  premise  implies  an  inference 
which,  in  reality,  it  does  not. 

The  intrinsic  source  of  aberrancies  consists  in  the  ques- 
tion at  issue  bearing  some  resemblance  to  another,  which 
is  essentially  different,  whence  it  is  apt  to  be  inferred 
that  the  former  is  proved,  when  the  latter  only  may 
have  been  proved.  (18) 

Inattention  is  the  immediate  extrinsic  cause  of  all  fal- 
lacies: for,  if  we  carefully  attend  to  a  subject,  we  shall 
know  whether  the  premises  are  sound,  whether  they  im- 
ply the  conclusion,  and  whether  the  one  established  is 
the  right  conclusion.  Fallacious  phenomena  often  lead 
to  false  inferences :  yet  the  appearances  are  real ;  and  no 
false  inferences  are  drawn  regarding  them,  wherever  we 
give  them  sufficient  attention. 


SEC.  1.]  CAUSES  OF  INATTENTION.  253 

Inattention  operates-  by  leading  us,  either  to  overlook 
something  altogether,  or  to  draw  immaterial  distinctions, 
or  to  overlook  characteristic  differences,  so  that  we  mis- 
take one  thing  for  another. 

In  order  to  secure  attention,  we  must  ascertain  the 
causes  of  inattention,  of  which  the  following  are  the 
principal. 

1.  The  painf  idness  of  close  and  continued  attention. 
This  generally  requires  a  strong  and  unpleasant  effort : 
for  the  mind  naturally  tends  to  run  off  from  the  point 
under  consideration  to  something  else,  which  it  suggests, 
and  which  it  is  less  irksome  to  contemplate,  while  we 
are  glad  to  avoid  the  painful  feeling  of  exhaustion  which 
such  attention  produces.     Hence  investigation  is  often 
hurried  ;  and  various  points  are  considered  inattentively, 
as  the  mind  wanders  from  the  subject,  before  we  have 
obtained  either  an  accurate  or  an  extensive  insight  into  it. 

2.  The  sacrifice  of  present  enjoyment  often  involved  in 
continued  attention.     The  earnest  investigator  must  oft- 
en deny  himself  many  pleasures  which  are  freely  enjoyed 
by  others,  as  when  he  sits  in  silence,  pondering  over  dif- 
ficulties, or  when  he  is  busy  amid  objects  offensive  to  his 
senses,  while  his  friends  are  enjoying  the  pleasures  of 
social  intercourse,  or  the  beauties  of  external  nature. 

The  two  preceding  causes  generally  operate  simulta- 
neously on  the  individual,  and,  owing  to  their  combined 
influence,  the  attention  often  wanders  from  the  subject ; 
things  are  viewed  hurriedly  and  inaccurately;  conclu- 
sions are  adopted  or  rejected  without  proper  investiga- 
tion ;  and  erroneous  opinions  result. 

3.  Thinking  of  too  many  things  at  once.     The  atten- 
tion to  any  point  becomes  less  and  less,  as  the  number 
of  objects  to  which  it  is  directed  increases,  supposing 
that  none  of  them  excite  it  strongly.     Hence  a  person 
who  thinks  at  once  of  several  things,  each  of  which  re- 
quires close  attention,  is  very  liable  to  err  regarding  one 
or  more  of  them. 

4.  Strong  sensations  or  perceptions.     When  a  person 
endures  acute  pain,  or  has  his  attention  forced  on  some 
strong  perception,  such  as  the  discharge  of  a  gun  very 
near  him,  it  is  generally  impossible  to  attend  either  close- 
ly or  continuously  to  the  matter  in  hand.     Even  moder- 
ate pain,  if  continuous,  such  as  hunger  and  thirst,  distract 
the  attention,  in  ordinary  circumstances,  to  such  a  de- 


254  SOURCES  OF  FALLACIES.      [CHAP.  XVI. 

§ree  as  to  render  the  investigation  quite  unreliable, 
trong  pleasing  sensations  are  equally  unfavorable  to  the 
discovery  of  truth.  A  person  whose  ear  is  delighted 
with  sweet  music,  or  who  views  a  very  striking  and  beau- 
tiful scene,  for  the  first  time,  need  not  hope  to  solve  any 
difficult  problem.  In  all  such  cases,  the  attention  is 
drawn  so  powerfully  to  the  apprehension,  that  we  can- 
not examine  another  subject  with  any  degree  of  care. 

5.  Obtuseness  of  the  faculties,  arising  from  fatigue, 
disorder,  or  some  permanent  defect.    A  person  who  is 
sleepy,  or  suffering  under  the  influence  of  a  narcotic 
drug,  cannot  pay  close  attention  to  anything  which  does 
not  produce  unusually  strong  feelings ;  and  the  same  re- 
mark applies  to  one  who  is  prostrated  by  strong  previ- 
ous excitement,  or  whose  faculties  are  naturally  very  dull 
and  torpid. 

6.  Strong  emotions,  unconnected  with  the  subject  of  in- 
vestigation.    These  distract  the  attention  quite  as  much 
as  strong  apprehensions,  and  operate  precisely  in  the 
same  way.     A  man  who  is  excited  with  wrath,  or  in  a 
paroxysm  of  joy,  is  as  unfit  for  investigation  as  if  he  were 
laboring  under  a  burning  fever,  although  his  passion 
should  be  entirely  unconnected  with  the  subject  of  in- 
quiry. 

7.  Prejudices,  or  emotions  connected  with  the  subject 
of  investigation.     So  much  often  depends  on  the  conclu- 
sion at  which  we  may  arrive,  that  strong  feelings  are  ex- 
cited, which  mislead  us  like  other  emotions.     But  here 
we  are  less  apt  to  be  sensible  of  their  influence,  while,  at 
the  same  time,  this  is  more  constant,  and  not  so  easily 
avoided.     Hence  prejudices  are  the  most  fertile  of  all 
sources  of  error. 

§  2.  OF  PREJUDICES. — Modes  in  which  Prejudices  operate. — Causes 
of  their  power. — In  what  cases  they  exist. — Five  classes  of  Preju- 
dices, with  Remarks. — Combination  of  Prejudices. — Source  of  the 
power  of  Error. — Why  we  readily  take  for  granted  what  we  are 
taught. 

While  prejudices  distract  the  attention,  like  other  emo- 
tions, they  also  tend  to  withdraw  it  from  whatever  leads 
to  a  disagreeable  conclusion,  and  to  concentrate  it  on 
those  of  a  contrary  kind,  because  we  naturally  turn  away 
from  painful  feelings,  and  fix  the  attention  on  such  as  are 
agreeable,  just  as  we  turn  from  loathsome  sights  or  odors, 


SEC.  2.]  PREJUDICES.  255 

to  such  as  are  pleasant.  Hence  we  are  disposed,  not  only 
to  overlook  that  side  of  the  subject  which  makes  against 
the  conclusion  we  desire  to  be  true,  but  also  to  view  the 
other  side  as  being  brighter  or  stronger  than  the  reality, 
because  we  overlook  all  the  weak  and  hostile  parts  of  it, 
and  confine  our  attention  to  the  others. 

The  case  of  persons  who  take  a  more  gloomy  view  of 
a  subject  than  truth  warrants,  is  no  exception  to  this  re- 
mark :  for  security  against  some  anticipated  evil,  or  a 
deliverance  from  present  pain,  appears  to  them  extreme- 
ly desirable,  as  the  amount  of  evil  is  generally  exagger- 
ated, from  sgrne  mistaken  opinion,  or  a  timid  and  over- 
sensitive disposition. 

The  attention  is  thus  apt  to  be  confined  to  those  things 
which  make  either  for  or  against  the  conclusion,  while 
the  rest  of  the  subject  is  either  wholly  overlooked,  or  not 
considered  with  any  degree  of  care.  Hence  futile  dis- 
tinctions are  taken  for  essential  differences,  while  the  lat- 
ter are  either  overlooked  or  treated  as  immaterial,  and 
one  thing  is  mistaken  for  another,  of  a  widely  different 
character,  so  that  fallacious  arguments  are  adopted  as 
conclusive,  while  irrefragable  proofs  are  rejected  as  un- 
satisfactory. 

Not  unfrequently  the  Imagination  rivets  the  error,  by 
drawing  unfaithful  pictures,  which  are  taken  to  be  cor- 
rect, because  the  attention  is  so  absorbed  that  their  true 
character  is  not  perceived.  The  bright  parts  are  exag- 
gerated, because  their  worse  aspects  are  overlooked,  and 
imaginary  excellence  is  superadded,  while  the  dark  parts 
are  equally  misrepresented,  because  we  do  not  attend  to 
their  better  aspects,  and  we  attribute  to  them  imaginary 
evils.  At  the  same  time  the  emotions  excited  prevent 
us  from  adverting  to  the  fact  that  the  picture  is  only 
imaginary,  and  lacks  proof. 

The  influence  of  prejudices  is  very  apt  to  escape  our 
notice,  because  they  operate  rapidly,  quietly,  and  without 
any  noticeable  effort,  whence  their  power  is  increased, 
because  it  is  unperceived,  or  even  unsuspected.  Thus 
the  Judgement  becomes  the  dupe  of  the  feelings,  and 
we  unconsciously  form  very  false  opinions,  under  the 
partial  and  erroneous  views  of  a  subject  thus  produced. 
Such  opinions  are  often  held  with  great  tenacity,  because 
we  are  quite  unaware  of  the  deception  which  we  prac- 
tice upon  ourselves;  and  they  are  more  numerous  than 


250  SOURCES  OF  FALLACIES.      [CHAP.  XVI. 

the  fallacies  arising  from  other  emotions,  because  preju- 
dices operate  secretly  and  incessantly.  Every  important 
subject  generally  excites  some  prejudice,  which  arises 
quietly  and  operates,  in  a  great  measure,  undiscernibly, 
because  there  is  no  palpable  indication  of  its  presence, 
whereas  a  man  under  the  influence  of  violent  wrath,  or 
deep  grief,  is  apt  to  allow  his  emotion  to  subside,  before 
he  undertakes  to  investigate  any  subject  of  consequence ; 
and  he  has,  at  all  events,  a  distinct  knowledge  of  the  dis- 
advantage under  which  he  labors. 

The  influence  of  prejudices  is  strengthened  by  our  be- 
ing very  unwilling  to  believe  its  existence,  or  to  examine 
their  operation  aright.  It  is  mortifying  to  our  self-es- 
teem to  think  that  we  have  been  deceived  by  our  wish- 
es; nor  is  it  easy  to  understand  how  this  happens. 
Hence  many  never  acquire  that  knowledge  of  the  na- 
ture and  operation  of  prejudices  which  is  requisite  to 
guard  us  fully  against  their  influence. 

Prejudice  exists  wherever  strong  emotions  are  excited 
by  the  contemplation  of  the  results  at  which  we  may  ar- 
rive: for  these  feelings  excite  a  strong  desire  that  the 
proposition  under  consideration  should  be  true  or  false, 
owing  to  our  belief  regarding  the  good  or  evil  connected 
with  the  alternatives. 

As  all  prejudices  operate  in  the  same  way,  and  their 
number  is  indefinitely  great,  a  complete  enumeration  of 
them  is  neither  desirable  nor  practicable.  The  following 
are  the  most  common. 

1.  Prejudices  of  self-love  in  general.  Every  one  nec- 
essarily desires  his  own  welfare,  and  is,  therefore,  prone 
to  believe  whatever  tends  towards  that  object,  and  un- 
willing to  believe  the  reverse.  Hence  the  readiness  with 
which  youth  expects  a  happy  manhood,  and  the  latter 
believes  that  visionary  projects  are  highly  eligible. 
Hence,  also,  the  readiness  with  which  many  listen  to 
flattery,  or  fish  for  applause,  or  foster  pride,  by  believing 
that  they  and  their  kindred  are  superior  to  others. 
Hence  our  unwillingness  to  listen  to  reproof  and  bitter 
truths,  and  our  readiness  to  believe  agreeable  falsehoods, 
to  interpret  the  language  of  others  so  as  to  square  with 
our  views  and  wishes,  and  to  accept  or  reject  their  testi- 
monies, according  as  it  is  agreeable  or  the  reverse. 
Hence  we  are  apt  to  form  too  high  an  opinion  of  our- 
selves and  what  concerns  us,  and  too  low  an  estimate  of 


SEC.  2.]  PREJUDICES.  257 

others.  Hence,  also,  the  undue  value  we  often  attach  to 
what  affects  our  own  welfare,  and  the  underestimate  we 
make  of  what  concerns  our  neighbour's ;  and  hence  our 
unwillingness  to  believe  that  our  own  characters,  views, 
opinions  and  prospects  are  bad. 

2.  Prejudices  of  the  ruling  desire.     A  great  portion  of 
mankind  consider  some  particular  thing  much  more  val- 
uable than  any  other  good;  and  hence  they  desire  it 
with  corresponding  earnestness  and  constancy.     Every- 
thing is  viewed  under  the  influence  of  this  prejudice; 
and  nothing  is  patiently  considered  which  tends  to  prove 
that  the  object  of  pursuit  is  unworthy  of  such  anxieties 
and  toils,  or  that  there  is  something  else  of  much  more 
consequence.     A  miser  will  not  consider  the  evils  inci- 
dent to  an  inordinate  pursuit  of  gain  ;  and  a  vain  person 
is  unwilling  to  believe  that  his  flatterers  are  either  mock- 
ers or  designing  knaves,  although  this  may  be  very  ap- 
parent to  others.     The  man  who  makes  reputation  his 
chief  good,  rejects  all  arguments  to  prove  that  he  is  pur- 
suing a  shadow ;  and  the  sensualist  will  listen  to  nothing 
which  goes  to  prove  that  there  is  anything  within  his 
reach  of  vastly  more  importance  than  sensual  gratifica- 
tions. 

3.  Prejudices  arising  from  the  love  of  present  ease  or 
enjoyment^  and  an  aversion  to  present  toil  or  suffering. 
What  is  present,  or  in  immediate  view,  is  easily  appre- 
ciated, and  if  it  be  deemed  of  much  consequence,  it  usual- 
ly excites  a  strong  desire  to  secure  or  avoid  it.     But  the 
case  is  far  otherwise  with  the  distant  future.     This  gen- 
erally requires  careful  consideration,  in  order  to  be  prop- 
erly estimated,  because  remote  objects  appear  indistinct 
and  smaller  than  the  reality  to  mental,  as  they  do  to  ocu- 
lar, vision ;  and,  in  many  instances,  the  real  character  of 
the  future  can  be  ascertained  only  by  means  of  continued 
and  painful  efforts,  which  all  dislike,  and  which  an  ex- 
amination of  the  present  does  not  involve.     At  the  same 
time  the  attention  is  naturally  drawn  first  to  that  which 
is  near,  as  being  the  most  striking,  and  often  the  most 
urgent ;  and  the  anticipation  of  speedy  pleasure  or  pain 
withdraws  it  from  a  careful  consideration  of  the  future, 
which  is  also  less  vividly  pictured  by  Conception.   Hence, 
when  the  choice  lay  between  the  present  and  the  future, 
mankind  have  frequently  preferred   the  former,  even 
where  the  latter  was  incomparably  more  important. 


258  SOURCES  or  FALLACIES.     [CHAP.  XVI. 

From  this  prejudice  originates  the  practice  of  taking 
up  a  subject,  and  studying  it  only  till  its  novelty  has 
ceased  to  tickle  the  fancy,  when  it  gives  place  to  some 
other,  which  soon  makes  way  for  a  third,  and  so  to  the 
end  of  the  cycle.  In  this  way  many  have  become  proud 
of  their  attainments,  when,  in  truth,  they  never  mastered 
the  rudiments  of  a  single  important  study.  A  similar 
effect  of  this  prejudice  is,  the  common  predilection  for 
such  methods  as  profess  to  furnish  a  short  and  easy  road 
to  knowledge,  and  the  dislike  for  such  as  require  a  great 
degree  of  labor,  and  also  the  predilection  for  those  stud- 
ies which  either  please  at  the  time  or  promise  the  speedy 
gratification  of  some  favorite  desire,  in  preference  to 
those  of  a  contrary  character,  though  the  latter  are  gen- 
erally by  far  the  most  important. 

From  the  same  source  has  originated  many  false 
maxims,  such  as  that  all  valuable  truth  is  easily  acquired, 
that  whatever  is  unknown  must  be  of  little  value,  that  our 
faculties  are  very  blind  and  weak,  that  we  can  know  very 
little  at  the  best,  and  that  all  real  knowledge  is  very 
simple.  Although  it  is  easily  seen  that  all  such  dogmas 
are  false,  yet,  with  their  aid,  many  contrive  to  keep 
themselves  very  ignorant  of  various  truths  which  it  deep- 
ly concerns  them  to  know,  while  they  adopt  errors  in 
their  stead,  without  ever  suspecting  that  all  is  not  right. 

Another  instance  of  the  effects  of  this  prejudice  is,  the 
dislike  which  men  swayed  by  evil  desires  or  groveling 
appetites  bear  to  true  religion  and  sound  morality.  These 
militate  against  their  present  enjoyments.  Hence  they 
generally  ly  to  religious  scepticism,  fanaticism,  or  super- 
stition, any  of  which  is  more  conformable  to  their  wishes 
than  truth;  and  consequently  the  same  person  often 
swings  repeatedly  from  one  to  another  of  these  errors. 

Another  frequent  instance  is,  the  devotion  to  that 
course  which  promises  most  money.  This  commands 
various  immediate  pleasures,  while  it  secures  men  against 
various  present  pains,  and  hence  the  avidity  with  which 
it  has  been  sought  by  the  countless  votaries  of  Mammon. 
The  preference  of  sensual  to  mental  gratifications  is  an 
equally  common  instance.  The  former  can  be  enjoyed 
without  any  previous  study  or  self-denial. 

From  this  prejudice  also  springs  that  fondness  which 
many  show,  for  adhering  uniformly  to  general  rules  or 
modes  of  acting,  however  requisite  modifications  or  dc- 


SEC.  2.]  PREJUDICES.  259 

viations  may  be,  in  certain  instances.  Hence  they  fre- 
quently run  from  one  extreme  to  another.  If  they  get 
into  serious  trouble,  from  following  their  usual  course, 
they  are  apt  to  discard  all  rules ;  and  if  they  find  that 
some  of  their  opinions  are  not  wholly  true,  they  will 
probably  reject  them  altogether,  and  adopt  the  contrary, 
which  may  be  more  erroneous  than  the  former. 

4.  Prejudices  of  education  and  profession.    The  ha- 
bitual consideration  of  some  objects,  or  parts  of  a  sub- 
ject, to  the  exclusion  of  others,  tends  to  produce  very 
erroneous  opinions,  since  we  attach  little  importance  to 
that  of  which  we  are  ignorant.     Hence  those  objects 
often  excite  emotions  and  desires  extremely  dispropor- 
tionate to  their  real  importance.     The  subjects  which  we 
have  been  taught  in  youth,  and  those  things  with  which 
our  vocation  makes  us  familiar,  are  frequently  viewed 
through  this  distorting  medium,  and  seem  very  different 
from  the  reality,  while  we  test  everything  by  that  with 
Avhich  we  are  familiar,  however  inapplicable.     Every 
bigot  thinks  that  saving  truth  is  found  with  his  creed 
alone :  the  artisan  is  apt  to  think  that  his  art  is  the  most 
important,  ingenious  or  beautiful  in  the  world :  the  mer- 
chant is  inclined  to  apply  figures  to  everything,  and  to 
estimate  the  character  and  prosperity  of  a  nation  by  its 
exports  and  imports ;  and  the  mathematician  sometimes 
attempts  to  improve  mental  science  by  very  rigid  argu- 
ments, based  on  specious,  but  inaccurate,  definitions,  and 
plausible,  but  erroneous,  assumptions,  leading  to  irrele- 
vant conclusions.     So  every  nation  and  class  are  apt'to 
think  more  favorably  of  their  own  institutions,  laws,  cus- 
toms, and  manners  than  would  be  warranted  by  an  im- 
partial judgement. 

5.  Prejudices  of  association.     It  often  happens  that 
things  are  associated  in  our  minds  with  excellences  or 
defects  with  which  they  have  no  necessary  and  uniform 
connection,  whence  the  contemplation  of  them  excites 
emotions  which  properly  belong  to  the  latter,  but  which 
are  referred  to  the  former,  as  their  cause.    Consequently 
they  are  judged  according  to  those  emotions,  and  very 
erroneous  opinions  are  formed  regarding  their  real  na- 
ture.    A  person,  for  instance,  flatters  those  whom*  he  ad- 
dresses.   This  pleases  them ;  and  they  attribute  the  pleas- 
ure to  his  superior  judgement,  the  excellence  of  his  argu- 
ments, or  the  goodness  of  his  cause.     Hence  flattery  has 


260  SOUECES  OF  FALLACIES.      [CHAP.  XVI. 

ever  been  a  powerful  instrument  of  deception.  One  man 
has  a  repulsive  aspect,  and  hence  a  prejudice  against 
his  sentiments :  another  appears  benevolent,  and  hence  a 
prejudice  in  favor  of  his  opinions. 

This  class  of  prejudices  has  produced  much  evil 
throughout  the  world.  The  heathen  has  often  clung  to 
his  gods,  and  rejected  the  clearest  proofs  that  they  are 
only -imaginary  monsters,  because  their  worship  was  as- 
sociated with  his  domestic  joys,  and  they  did  not  pro- 
hibit wicked  practices  to  which  he  was  strongly  attach- 
ed. So  the  child,  whose  vicious  propensities  were  curb- 
ed by  his  parents  and  teachers,  has  often  been  prejudiced, 
on  that  account,  against  the  truths  which  they  inculca- 
ted, while  another,  whose  wicked  inclinations  were  free- 
ly indulged,  was  strongly  prejudiced  in  favor  of  the  false 
teachings  of  those  who  so  indulged  him.  Men  are  thus 
very  apt  to  be  prejudiced  in  favor  of  false  opinions  which 
accord  with  their  vices ;  and  here  lies  the  power  of  error. 

Prejudices  often  derive  force  from  the  combination  of 
several,  to  produce  the  same  result.  A  man,  for  instance, 
is  strongly  prejudiced  in  favor  of  his  own  views  or  opin- 
ions, because  it  is  humiliating  to  think  that  he  has  been 
mistaken ;  he  has  been  so  taught  by  his  parents  or  teach- 
ers, whom  he  venerates ;  if  he  should  be  in  error,  he  must 
undergo  the  labor  of  re-examination  ;  and  possibly  he 
may  arrive  at  conclusions  repugnant  to  his  ruling  de- 
sires, and  tending  to  render  him  less  acceptable  to  per- 
sons whose  good  opinion  he  wishes  to  possess. 

From  such  sources  originates  the  common  practice  of 
taking  for  true  what  we  nave  been  taught  or  have  hith- 
erto believed,  and  looking  to  the  mere  opinions  of  others, 
instead  of  searching  for  conclusive  proof.  It  is  so  much 
more  pleasant  and  easy  to  accept  current  opinions,  which 
tally  with  our  wishes,  and  to  compare  and  criticise  writ- 
ten statements,  than  to  investigate  the  subject  properly 
for  ourselves,  that  we  need  not  wonder  a  large  portion 
of  mankind  have  adopted,  from  the  earliest  times,  error 
which  a  very  moderate  degree  of  independent  and  care- 
ful observation  and  reasoning  would  have  completely  ex- 
ploded. 

§  3.  MEANS  or  AVOIDING  FALLACIES. — Requisites  in  order  to  avoid 
Fallacies. — Means  of  obviating  the  influence  of  Prejudices. — Two 
important  means  of  avoiding  Error. — Why  Truth  is  often  under- 
valued.— Consequences. — Proper  Course. — Dangerous  Practice. — 


SEC.  3.]  MEANS  OF  AVOIDING  THEM.  261 

Evil  results  of  one  fundamental  Error,  and  of  misdirected  Activity. 
— How  important  Conclusions  should  be  tested. — Synopses. — Ar- 
guments which  prove  too  much. — Means  of  counteracting  the  ef- 
fects of  Prejudices. — Refuting  and  proving  Arguments. — Usual 
tendency  of  the  Mind,  and  consequent  Caution.  —  Exception.  — 
Common  Error. 

In  order  to  avoid  erroneous  opinions,  we  must  atten- 
tively examine  everything  requisite  to  obtain  a  correct 
view  of  the  subject  under  consideration ;  and  this  re- 
quires that  we  avoid  the  various  sources  of  inattention. 
Hence  we  should  never  study  or  investigate  any  subject 
while  we  are  influenced  by  a  feeling  or  perception  so 
strong  that  we  cannot  readily  concentrate  our  attention 
on  any  point  at  will,  or  while  our  faculties  are  blunted 
by  sleepiness,  languor,  stupor,  fatigue,  exhaustion,  or 
bodily  disorder,  so  that  we  cannot  pay  close  attention 
to  the  subject;  nor  should  any  confidence  be  placed  in 
•  conclusions  formed  under  such  circumstances. 

We  should  guard  against  strong  apprehensions  and 
emotions,  by  keeping  at  a  distance  from  their  various 
sources,  such  as  exposure  to  great  heat  or  cold,  sensual 
habits,  loud  noises,  and  exciting  scenes,  conversation  or 
reading.  Sensual  habits  are  particularly  injurious,  be- 
cause they  produce  unnaturally  powerful  appetites  for 
particular  indulgences,  which  greatly  distract  attention, 
and  at  the  same  time  cause  a  languid  and  irritable  state 
of  mind,  very  favorable  to  the  adoption  of  error.  Pas- 
sions operate  in  the  same  way:  but  their  influence  is 
much  less  extensive,  because  they  are  much  less  perma- 
nent in  their  effects. 

We  should  also  beware  of  having  our  attention  dis- 
tracted by  considering  several  things  at  once :  and  hence 
an  investigation  should  be  subdivided  into  parts,  every 
one  of  which  can  be  closely  examined,  and  its  character 
determined,  without  paying  any  attention  to  the  rest, 
during  its  examination. 

No  subject  should  ever  be  considered  negligently  or 
inattentively.  If  it  does  not  deserve  careful  attention, 
it  were  better  let  alone:  for  otherwise  we  shall  be  apt 
to  form  a  habit  of  inattentive  examination,  which  will 
cleave  to  us  in  investigating  the  most  important  subjects. 

The  principal  means  of  obviating  the  influence  of 
prejudices  is,  to  study  their  mode  of  operating,  once  for 
all,  until  we  see  the  inevitable  consequences  of  yielding 


262  SOUKCES  OF  FALLACIES.      [CHAP.  XVI. 

to  their  influence,  to  mark  the  nature  and  tendency  of 
our  special  prejudices  regarding  the  immediate  subject 
under  consideration,  and  to  cherish  the  dispositions  and 
habits  requisite  for  proper  study  and  investigation.  If 
we  allow  our  minds  to  be  controlled  by  prejudice,  the 
flood-gates  of  error  are  thrown  open,  and  we  readily 
adopt  it  instead  of  truth,  without  ever  suspecting  the  de- 
ception. We  should  distinguish  the  question  before  us 
from  those  which  prejudice  leads  us  to  substitute  for  it, 
and  to  examine  it  aright,  on  its  own  merits,  regardless 
of  the  real  or  fancied  consequences. 

It  is  frequently  impossible  to  eradicate  a  prejudice: 
yet  its  mere  existence  need  not  prevent  us  from  adhering 
to  all  the  principles  of  proper  investigation :  for  where 
conclusive  proof  is  fairly  understood,  it  necessarily  pro- 
duces conviction,  however  disagreeable  the  conclusion, 
as  when  a  man  hears  very  bad  news,  and  the  testimony 
leaves  no  room  to  doubt  its  truth,  or  opens  his  purse, 
thinking  it  contains  money  to  pay  a  demand  made  on 
him,  and  finds  it  empty.  Prejudice  can  mislead  us  only 
by  withdrawing  or  distracting  the  attention :  and,  there- 
fore, if  this  can  be  sufficiently  secured,  the  subject  will 
be  seen  in  its  true  light,  whether  pleasant  or  the  reverse. 

We  shall  be  greatly  aided  in  overcoming  the  influence 
of  prejudice,  by  forming  a  proper  estimate  of  the  value 
of  truth,  and  habituating  ourselves  to  endure  a  little 
present  evil,  for  the  sake  of  a  great  future  good :  for 
prejudices  derive  their  force  chiefly  from  the  induce- 
ments which  they  hold  out  to  sacrifice  the  long  future 
for  the  present  moment.  The  discovery  of  truth  may 
hurt  our  feelings  for  a  little  while :  but,  like  a  surgical 
operation,  it  has  a  healing  effect. 

Prejudices  are  often  on  the  side  of  truth :  but,  even 
here,  they  are  apt  to  act  injuriously,  by  preventing  a 
proper  examination  of  the  subject.  Thus,  they  may  pre- 
vent us  from  knowing  the  real  grounds  of  our  opinions, 
and  the  futility  of  plausible  objections  and  counter  argu- 
ments, so  that  when  the  advocates  of  error  afterwards 
assail  us  with  these  weapons,  we  are  liable  to  be  much 
perplexed,  if  not  permanently  misled. 

A  knowledge  of  the  great  value  of  truth  and  the  vast 
importance  of  the  future,  forms  one  of  the  most  import- 
ant means  of  avoiding  error.  Mankind  do  and  suffer 
much  for  the  sake  of  gain ;  and,  as  truth  is  of  incom- 


SEC.  3.]  MEANS  OF  AVOIDING  THEM.  263 

parably  more  importance  than  money,  they  will  readily 
make  much  greater  sacrifices  for  its  attainment  wherever 
they  understand  its  worth,  while  those  actually  required 
are  much  less.  The  self-denial,  toil  and  suffering  often 
undergone  for  the  sake  of  gold,  greatly  exceed  anything 
which  the  proper  pursuit  of  truth  demands,  although, 
like  every  real  good,  it  requires  sacrifices. 

In  order,  however,  to  know  the  value  of  truth,  it  is 
often  necessary  to  look  steadily  into  the  future ;  and  this 
is  strongly  opposed  by  the  desire  of  immediate  enjoy- 
ment, and  the  aversion  to  present  toil  or  suffering.  Hence 
truth  is  often  exceedingly  undervalued ;  and  men  fly  to 
false  maxims  or  opinions,  to  justify  themselves  in  neglect- 
ing to  search  for  it  aright.  It. is  assumed,  for  instance, 
that  all  important  truth  is  easily  discovered ;  and  then 
the  dictates  of  prejudice,  the  illusions  of  the  senses,  or 
the  deceptions  of  knavery,  are  received  as  truths  that  re- 
quire no  further  examination,  and  ought  not  to  be  doubt- 
ed. Or,  it  is  assumed  that  nothing  can  be  certainly 
known,  and,  therefore,  it  matters  little  what  we  believe. 

Errors  of  this  kind  should  be  carefully  avoided :  for 
they  undermine  the  very  foundations  of  knowledge. 
There  is  no  more  important  requisite  for  right  investiga- 
tion than  correct  views  of  its  value ;  and  the  absence  of 
it  is  a  most  fruitful  source  of  error.  False  maxims  and 
opinions,  such  as  those  just  adverted  to,  are  so  frequent- 
ly echoed  from  man  to  man,  and  chime  in  so  exactly 
with  our  wishes,  that  they  have  imposed  on  the  great 
majority  of  mankind,  from  the  earliest  times,  and,  by  pre- 
venting due  investigation,  led  them  to  adopt  error  in  the 
place  of  truth. 

In  order  to  understand  any  important  subject  correct- 
ly, we  must  always  labor  on  things  which  are  intrinsic- 
ally uninviting,  if  not  unpleasant,  but  which  are  inter- 
esting as  necessary  means  to  future  results.  We  should 
beware  of  the  childish  practice  of  looking  only  at  whnt 
is  near,  and  overlooking  all  beyond  as  of  little  conse- 
quence :  else  we  shall  allow  things  comparatively  trifling 
to  set  aside  the  consideration  of  the  most  momentous 
subjects,  and  resemble  a  man  journeying  on  very  import- 
ant business,  who  lost  his  object,  by  turning  aside  to 
gather  flowers.  Everything  should  be  estimated  at  its 
real  value,  without  making  any  distinction  between  the 
present  and  the  future,  since  the  former  is  incessantly 
vanishing  and  giving  place  to  the  latter. 


264  SOURCES  OP  FALLACIES.      [CHAP.  XVI. 

Some  are  quite  satisfied  to  believe  like  their  friends ; 
and  these,  in  their  turn,  think  they  are  safe  in  imitating 
the  former,  when  possibly  all  are  equally  in  error,  and 
they  are  mutually  confirming  each  other  in  false  opinions. 

The  importance  of  care,  at  every  step  of  our  investi- 
gations, appears  from  the  facts,  that  one  error  may  lead 
to  many  others,  as  sure  consequences,  and  that  a  mistake 
on  a  single  point  may  mislead  us  regarding  the  whole 
subject.  It  is  often  impossible  to  foresee  the  future  ef- 
fects of  a  certain  conclusion ;  and  hence  we  are  liable  to 
attach  little  importance  to  points  which  may  be  of  the 
utmost  consequence.  If  a  man  radically  err  regarding 
the  doctrines  of  causation  and  free  agency,  for  example, 
all  his  opinions  regarding  God  and  duty  will  be  little 
more  than  a  tissue  of  errors,  in  which  one  fallacy  sup- 
ports another ;  and  a  man  who  believes  that  we  cannot 
acquire  any  certain  knowledge,  will  never  be  successful 
in  its  pursuit. 

Mere  feebleness  of  intellect  rather  fosters  ignorance 
than  leads  to  positive  error,  since  there  is  inaction,  and 
not  misdirected  action.  Hence  idiots  never  adopt  many 
errors  which  have  been  held  by  men  of  great  abilities, 
into  which  they  were  led  by  prejudices  and  ill-regulated 
feelings. 

Every  conclusion  should  be  carefully  traced,  step  by 
step,  to  its  foundations ;  and  none  should  be  admitted 
as  true  unless  the  proof  is  found  conclusive.  In  cases  of 
difficulty  and  importance,  it  is  proper  to  write  a  synop- 
sis of  the  whole  proof,  from  the  primary  premises  to  the 
conclusion,  omitting  all  unessential  matter,  and  laying 
down  every  part  in  its  proper  place.  The  synopsis  should 
then  be  scrutinized  till  we  know  that  we  have  carefully 
considered  every  part,  and  ascertained  its  true  character. 

Fallacious  arguments  frequently  pass  for  sound  reason- 
ing, because  they  are  interlarded  with  various  illustra- 
tions and  irrelevant  matters :  and,  therefore,  it  is  desir- 
able to  separate  the  essential  parts  from  the  rest,  and  ex- 
hibit the  argument  in  its  naked  and  most  concise  form, 
when  its  true  character  can  be  generally  ascertained  by 
a  little  close  attention  to  the  exact  nature  and  connection 
of  its  various  parts. 

Wherever  it  is  alleged  that  an  argument  proves  too 
much,  or  that  it  leads  to  some  false  conclusion,  we  ought 
to  examine  the  subject  till  we  have  certainly  ascertained 


Ssc.  3.]  MEANS  OF  AVOIDING  THEM.  265 

whether  it  does  so  or  not.  If  it  do,  it  is  unsound.  If  it 
do  not,  we  must  not  infer  that  it  is  conclusive,  as  it  may 
possibly  be  refutable  by  other  means ;  but  it  should  be 
tested  by  a  proper  examination.  Men  frequently  allege 
that  an  argument  which  establishes  a  conclusion  that 
conflicts  with  their  wishes  or  opinions,  proves  too  much 
when  such  is  by  no  means  the  case. 

Where  prejudices  are  possibly  concerned,  we  should 
compare  our  own  conclusions  with  those  of  persons  of 
opposite  prejudices,  if  such  there  be,  and  then  examine 
and  compare  the  arguments  on  each  side,  till  we  ascer- 
tain the  source  of  any  discrepancy  which  appears  in  the 
conclusions.  In  order  to  know  that  a  conclusion  is  true, 
it  is  not  sufficient  that  we  are  satisfied  and  firmly  believe 
it  is  so :  we  must  have  the  evidence  of  Consciousness,  at 
every  step,  as  was  formerly  stated ;  and  where  we  have 
obtained  such  evidence,  the  conclusions  are  no  longer 
opinions,  but  cognitions. 

We  should  never  slight  an  argument  which  professes 
to  prove  a  disagreeable  conclusion,  or  one  that  runs  coun- 
ter to  our  prejudices.  If  we  are  inclined  to  do  so,  we 
should  try  whether  we  can  refute  it,  or  demonstrate  its 
inconclusiveness  beyond  all  possibility  of  error,  a  course 
which  will  sometimes  show  us  that  it  is  irrefragable. 
On  the  other  hand,  we  should  most  rigidly  test  the 
soundness  of  arguments  which  prove  a  conclusion  that 
we  desire  to  be  true,  and  not  rest  satisfied  that  it  is  con- 
clusive till  there  is  no  possible  room  for  any  fallacy.  We 
shall  thus  be  likely  to  escape  the  numerous  errors  into 
which  we  are  liable  to  be  led  by  prejudices. 

The  Utjual  tendency  of  the  mind  is,  to  believe  too  read- 
ily what  it  wishes  to  be  true,  and  to  disbelieve  too  read- 
ily what  it  wishes  to  be  false.  Hence  we  should  be  par- 
ticularly circumspect  in  examining  proofs,  in  all  cases  of 
this  kind.  A  person  sometimes  hesitates  in  believing 
conclusive  evidence  of  an  agreeable  truth,  or  in  rejecting 
similar  proof  of  the  falsity  of  a  disagreeable  proposition  : 
but  this  is  only  an  exception  to  the  general  rule,  arising 
partly  from  the  antecedent  improbability  of  the  fact,  and 
partly  from  the  confusion  caused  by  the  strong  emotion 
excited.  Consequently  the  disbelief  generally  disappears 
as  soon  as  the  feeling  has  subsided,  and  the  matter  is 
viewed  more  calmly. 

As  the  sources  of  fallacy  are  very  numerous,  some 
M 


266  PARALOGISMS.  [CHAP.  XVII. 

have  concluded  that  we  can  be  positively  certain  of 
nothing.  But  the  fact  that  we  sometimes  adopt  errone- 
ous opinions,  by  no  means  proves  that  we  cannot  possess 
certain  knowledge.  A  proposition  which  conforms  to 
the  criterions  of  truth,  cannot  be  false,  although  we  some- 
times admit  those  of  a  different  character  as  true.  Our 
liability  to  err  should  teach  us  caution  in  forming  con- 
clusions, and  distrust  of  our  opinions  on  subjects  that  we 
have  never  properly  examined :  but  it  furnishes  no  good 
ground  for  scepticism  regarding  matters  where  no  fal- 
lacy can  exist. 


CHAPTER  XVII. 

OF    PAEALOGISMS,    OK    FALLACIES     OF    PEIMAKY    ASSUMP- 
TION. 

§  1.  PARALOGISMS  OF  INTUITION. — Intuitional  Assumption. — Intui- 
tional Kejection. — Sources  of  these  Fallacies. — Test  of  Intuitions. 

Intuitional  assumption  is,  assuming  a  proposition  as  a 
premise,  on  the  ground  that  it  is  self-evident,  when,  in 
reality,  it  is  not. 

Intuitional  rejection  occurs  where  a  self-evident  pre- 
mise is  rejected,  on  the  ground  that  it  is  untrue,  or  wants 
proof. 

The  former  of  these  paralogisms  arises  chiefly  from 
mistaking  very  familiar  propositions  for  intuitions,  from 
a  desire  to  extend  the  sphere  of  universal  truths,  or  from 
a  bias  in  favor  of  a  conclusion  which  the  supposed  intui- 
tion tends  to  establish.  We  are  disposed  to  assume  as 
self-evident  what  we  have  always  considered  such,  espe- 
cially where  the  proposition  proves  a  favorite  conclusion, 
or  saves  the  labor  of  close  and  continued  "observation. 
Hence  propositions  have  been  taken  for  intuitions  which 
are  self-evidently  impossible,  such  as  that  we  see  dis- 
tance. 

Intuitional  rejection  generally  proceeds  from  the  prop- 
osition's conflicting  with  some  cherished  belief,  or  its  ap- 
pearing novel  or  strange.  We  are  as  much  disposed  to 
reject  what  militates  against  the  truth  of  favorite  opin- 
ions as  we  are  inclined  to  receive,  without  due  caution, 
things  of  a  contrary  character.  Many  persons,  also, 


SEC.  2.]  TEST  OF  INTUITIONS.  267 

make  their  own  views  the  standard  of  truth,  and  unhesi- 
tatingly reject,  as  unworthy  of  being  deemed  self-evident, 
anything  which  never  appeared  to  them  in  that  light. 
Instances  of  this  occur  in  the  repeated  rejection  of  some 
intuitions  regarding  volitions  and  motives. 

To  determine  whether  a  proposition  is  self-evident,  we 
must  ascertain  exactly  what  it  is,  and  then  attentively 
consider  the  thing  meant,  apart  from  the  words  in  which 
it  may  have  been  expressed.  If  it  is  self-evident,  its 
truth  will  then  appear  clearly  and  irresistibly,  accom- 
panied with  a  discernment  that  it  cannot  by  possibility 
be  false,  and  that  its  contradictory  is'  an  utter  impossi- 
bility. The  criterion  of  intuitions  is,  as  the  name,  im- 
plies, that  the  attentive  mind  discerns  they  are  neces- 
sarily and  universally  true,  and  cannot  possibly  be  false, 
in  a  single  instance. 

The  self-evident  nature  of  intuitions  is  evinced  by  all 
persons  believing  and  acting  on  such  as  are  clearly 
brought  under  the  notice  of  their  understandings,  how- 
ever much  some  may  profess  to  repudiate  them.  When 
a  strange  event  occurs,  without  any  known  cause,  those 
who  maintain  that  causes  are  not  necessary  antecedents 
of  changes,  believe  there  must  be  a  cause,  while  there  is 
no  other  evidence  of  this  except  intuition.  Experience 
does  not  show  that  every  event  has  had  a  cause ;  for  we 
do  not  know  by  experience  that  many  events  ever  had 
a  cause ;  and  even  if  we  did,  this  would  not  prove  any- 
thing regarding  the  future.  The  experience  of  persons, 
in  the  various  zones,  regarding  the  apparent  positions 
and  the  risings  and  settings  of  the  heavenly  bodies,  are 
uniform,  and  yet  quite  different  from  their  neighbours'. 

§  2.  PARALOGISMS  OF  ASSUMING  WHAT  is  ATTEMPTED  TO  BE  PROVED. 
— Nature  of  these  Fallacies. — (1)  Assuming  the  Question. — Its 
Criterion. — (2)  Reasoning  in  a  Circle. — Its  Criterion. — Origin  of 
this  class  of  Fallacies. 

In  this  class  of  fallacies,  something  which  requires 
proof  is  assumed  as  a  primary  premise,  while  it  is  either 
virtually  identical  with  the  conclusion  or  is  inferred  from 
it,  although  the  reasoning  subsequent  to  the  assumption 
may  be  quite  valid.  It  includes  the  two  following  fal- 
lacies. 

1.  Assuming  (termed  also  begging)  the  question  is, 
where  we  assume,  as  a  primary  premise,  a  proposition. 


268  PARALOGISMS.  [CHAP.  XVII. 

which  requires  proof,  and  which  is  virtually  identical 
with  the  conclusion,  although  it  may  be  differently  ex- 
pressed. 

The  criterion  of  this  fallacy  is,  not  merely  the  identity 
of  the  primary  premise  with  the  conclusion,  but  also  that 
it  requires  proof,  which  is  not  given  :  for,  if  the  primary 
premise  requires  no  proof,  there  can  be  no  fallacy  of  pri- 
mary assumption.  Nor  would  the  argument  always  be 
useless,  since  we  may  rightly  assume  the  primary  premise 
without  seeing  that  it  is,  in  effect,  identical  with  the  con- 
clusion, because  the  latter  is  differently  expressed.  A 
person  often  admits  a  proposition  when  it  is  expressed 
in  one  form,  while  he  will  deny  it  under  another  form. 

Instances  of  this  fallacy  occur  in  those  cases  where 
the  premise  is  only  the  conclusion  expressed  in  learned 
phrase,  as  where  it  is  attempted  to  be  proved  that  we 
ought  to  do  a  thing,  on  the  assumption  that  we  are  un- 
der a  moral  obligation  to  do  so,  or  that  a  man  must  bo 
honest,  since  his  conduct  is  always  guided  by  principles 
of  moral  rectitude,  or  that  a  proposed  law  is  good,  since 
it  will  ameliorate  the  condition  of  the  people,  or  that  a 
politician  cherishes  no  selfish  views,  since  he  is  a  disin- 
terested patriot,  or  that  our  views  are  right,  since  they 
are  orthodox,  and  our  opponents  wrong,  since  they  are 
heterodox. 

2.  Reasoning  in  a  circle  (termed  also  the  vicious  cir- 
cle] is,  where  we  either  assume,  as  a  primary  premise,  an 
inference  from  the  conclusion  and  provable  only  by  means 
of  it,  or  attempt  to  deduce  our  first  assumption  from  the 
conclusion  inferred  from  it.  In  the  former  case,  we  first 
assume  the  inference,  and  then  attempt  to  deduce  the 
conclusion  from  it,  while,  in  reality,  the  assumption  re- 
quires proof,  and  can  be  proved  only  by  means  of  the 
conclusion  which  it  is  employed  to  establish.  In  the  lat- 
ter case,  the  conclusion  is  first  proved  by  means  of  the 
premise,  and  the  latter  is  then  proved  by  means  of  the 
former.  Both  processes  may  be  compared  to  an  attempt 
to  make  the  top  of  a  house  serve  for  its  foundation. 

The  criterion  of  this  fallacy  is,  that  something  is  as- 
sumed which  requires  to  be  proved  by  means  of  the  con- 
clusion inferred  from  it.  A  frequent  instance  of  it  is, 
assuming  a  proposition  generally,  and  then  attempting 
to  prove  a  particular  case  of  it,  by  means  of  this  assump- 
tion, when,  in  fact,  the  former  assumption  requires  proof, 


SEC.  3.]  MISCOMPKEHENSION.  269 

which  cannot  be  given  otherwise  than  by  means  of  the 
latter.  It  is  assumed,  for  instance,  that  all  men  are  mor- 
tal, and  from  this  it  is  very  easy  to  prove  that  A,  B,  or 
C  is  mortal.  The  principal  difficulty  lies  in  proving  the 
assumption,  which  cannot  be  rigidly  done  at  all,  and 
which  can  be  even  proved  to  hold  true  generally  only  by 
assuming  that  some 'men  are  mortal. 

Another  common  instance  is,  where  we  take  the  word 
of  a  stranger,  or  a  person  suspected  of  being  a  liar,  for 
his  own  integrity  or  veracity,  or  where  one  man's  verac- 
ity is  vouched  by  an  unknown  neighbour,  and  the  man 
himself  then  vouches  for  the  latter's  veracity.  This  has 
often  been  done,  where  all  the  parties  were  rascals,  col- 
leagued  with  each  other. 

Both  these  kinds  of  paralogism  are  frequently  derived 
from  false  systems  of  philosophy  or  science :  but  they 
may  also  proceed  from  inattention  in  our  own  investiga- 
tions, in  which  we  should  guard  against  them,  by  attend- 
ing closely  to  the  nature  of  our  primary  assumptions. 

§  3.  PARALOGISMS  OF  COMPREHENSION. — (1)  Miscomprehension. — 
(2)  Incomprehension. — Influence  of  Intuitional  Assumptions. 

1.  Miscomprehension  occurs  where,  owing  to  a  want 
of  due  care  and  attention,  we  overlook  or  mistake  char- 
acteristic marks  and  distinctions,  whence  we  mistake  one 
thing  for  another,  or  attribute  to  a  subject  something 
which  does  not,  in  reality,  belong  to  it.  A  common  in- 
stance of  it  is,  where  we  attribute  to  one  thing  what  re- 
ally belongs  to  another,  with  which  it  is  associated,  as 
when  we  erroneously  fancy  that  certain  forms  and  colors 
are  beautiful  because  they  are  associated  with  something 
that  is  so,  or  think  that  the  appearance  of  a  person  who 
has  wounded  our  feelings  is  disagreeable,  when  it  is  the 
reverse,  or  that  some  insipid  substance  has  an  agreeable 
taste  because  it  is  fragrant.  In  the  same  way  we  some- 
times falsely  attribute  a  certain  character  to  a  person, 
because  there  is  something  in  his  dress  or  appearance 
which  we  have  erroneously  associated  with  that  charac- 
ter. Another  common  instance  is,  where  we  mistake  one 
person  for  another,  because  we  have  not  sufficiently  at- 
tended to  their  distinctive  differences. 

Strong  emotions,  especially  when  the  organs  are  unfa- 
vorably situated,  often  produce  this  fallacy.  A  timid 
man,  in  a  lonely  forest  at  night,  is  very  apt  to  take  every 


270  PARALOGISMS.  [CHAP.  XVII. 

black  log  for  a  bear,  and  every  gray  stone  for  a  wolf. 
His  fear  causes  vivid  ideas  of  these  animals,  to  which  the 
things  apprehended  afford  a  basis  of  reality.  So,  when  a 
person  is  very  anxious  to  see  a  particular  thing,  or  when 
it  is  suggested  to  him  by  others,  a  vivid  similitude  of  it 
arises  before  his  mind,  and  if  there  is  anything  visible  to 
which  it  bears  the  least  resemblance,  on  which  it  can  be 
superinduced,  he  blends  the  two  objects,  and  readily  be- 
lieves that  he  perceives  the  prototype  of  the  similitude. 
It  is  thus  that  a  man  in  a  dim  light  sometimes  thinks  he 
sees  various  objects,  when  he  perceives  only  things  which 
somewhat  resemble  them. 

2.  Incomprehension  occurs  where  the  whole  of  a  sub- 
ject does  not  present  itself  to  our  view  at  once,  but  we 
discern  only  a  part,  and  then  assume  that  we  have  com- 
prehended the  whole.  We  should  remember  that  many 
facts  may  often  be  observed,- which  tend  to  prove  a  cer- 
tain conclusion,  while  possibly  more  may  be  found  on  the 
other  side,  which  are  very  apt  to  be  overlooked,  when 
they  oppugn  some  favorite  opinion.  The  particular  facts 
overlooked  depend  greatly  on  the  individual's  views  and 
feelings,  so  that  one  overlooks  the  very  things  which  an- 
other observes,  and  the  latter  overlooks  all  that  the  for- 
mer observes. 

A  common  instance  of  this  fallacy  is,  where  one  thing 
is  assumed  to  be  a  sure  sign  of  another  as  uniform  ante- 
cedent, concomitant,  or  consequent,  when  farther  observ- 
ation would  show  that  it  is  no  such  thing.  Many  super- 
stitious opinions  originate  in  this  way,  such  as  the  belief 
in  omens,  prodigies,  lucky  and  unlucky  days,  places,  and 
persons,  dreams,  fortune-telling,  and  the  power  of  charms 
and  incantations,  although,  in  producing  these  results, 
the  paralogism  is  generally  combined  with  the  sophisms 
of  causation  and  generalization. 

In  cases  of  this  kind  the  instances  which  favor  the  con- 
clusion are  carefully  noted  and  remembered,  while  the 
other,  and  much  more  numerous,  class,  are  either  wholly 
overlooked  or  forgotten.  When  a  quack  descants  on  the 
supposed  cures  alleged  to  have  been  effected  by  his  nos- 
trum, he  says  nothing  of  the  much  greater  number  of 
cases  in  which  no  benefit  was  derived  from  it,  or  it  even 
produced  serious  evil. 

Another  common  case  of  this  paralogism  is,  assuming 
that  a  few  individuals  of  a  class  which  we  may  have  seen 


SEC.  4.]  ILLUSIVE  SIGN.  271 

or  known,  are  fair  specimens  of  the  whole,  when  there  is 
no  proof  of  this,  and  the  fact  may  possibly  be  the  reverse. 
Some  travelers  describe  the  character  of  a  foreign  nation, 
when,  in  truth,  they  never  saw  one  of  them  in  his  ordi- 
nary mode  of  life,  except  innkeepers  and  their  servants. 
So  people  have  not  unfrequently  formed  an  erroneous 
opinion  of  mankind  at  large,  from  the  general  character 
of  their  friends  and  acquaintances. 

Another  frequent  instance  is,  assuming  that  the  mode 
of  effecting  a  certain  end,  with  which  we  are  familiar,  is 
the  only  one,  or  at  least  the  best,  whereas  several  better 
ways  may  be  known  to  others. 

Another  common  case  is,  where  a  person  thinks  he 
can  safely  afford  to  purchase  several  things,  because  he 
can  purchase  any  one  of  them  without  inconvenience. 
He  never  considers  the  result  of  purchasing  the  whole 
of  them,  but  while  he  thinks  of  some,  he  overlooks  the 
rest. 

Fallacies  of  comprehension  are  greatly  fostered  by  in- 
tuitional assumptions,  which  often  lead  us  to  think,  either 
that  no  observation  is  requisite,  or  that  we  have  already 
comprehended  enough,  when  the  case  may  be  far  other- 
wise. For  we  are  not  disposed  to  seek  for  proofs  of 
what  we  deem  self-evident,  nor  to  search  for  further 
proof  where  we  are  already  satisfied,  though  without  any 
good  ground. 

§  4.  PARALOGISMS  or  SIGNS. — (1)  Illusive  Sign. — Its  various  Sources. 
— Its  Character  and  Effects. — (2)  Non-interpretation  of  Signs. — 
Frequent  Combinations. 

Where  a  phenomenon  is  presented  to  our  observation 
which  appears,  and  which  we  assume,  to  signify  some- 
thing which,  in  reality,  it  does  not,  we  fall  into  the  paral- 
ogism of  illusive  sign.  It  differs  from  those  of  compre- 
hension in  our  being  misled  solely  by  drawing  a  false  in- 
ference, and  the  observation  not  being  necessarily  either 
careless  or  defective,  though,  in  fact,  it  often  is  so. 
When  we  view  a  statue  or  a  scarecrow,  and  take  it  for 
a  living  person,  or  when  we  look  at  the  images  produced 
on  a  screen  by  the  magic  lantern,  and  take  them  for  real 
pictures,  or  when  we  have  ringing  sounds  in  our  ears, 
and  attribute  them  to  some  external  source,  we  appre- 
hend the  phenomena  as  they  actually  are,  and  we  are 
misled  solely  by  drawing  erroneous  inferences.  So  cer- 


272  PARALOGISMS.  [CHAP.  XVII. 

tain  symptoms  are  often  inferred  to  indicate  a  particular 
disease,  when,  in  reality,  they  do  not,  because  they  equal- 
ly accompany  several  other  disorders.  Yet  the  symp- 
toms may  be  observed  with  perfect  accuracy,  and  it  may 
be  quite  true  that  they  always  accompany  the  disease 
which  they  are  erroneously  believed  to  indicate. 

We  readily  fall  into  this  fallacy  when  the  organs  of 
apprehension  are  diseased  or  defective.  When  the  optic 
nerves  are  inflamed,  the  ideas  of  objects  of  sight  some- 
times acquire  unusual  vividness ;  and  hence  they  are  mis- 
taken for  actual  apprehensions.  In  such  cases,  the  phe- 
nomena are  attributed  to  the  causes  which  usually  pro- 
duce similar  phenomena,  as  these  most  readily  occur  to 
our  minds. 

Prejudices  sometimes  produce  this  fallacy,  even  where 
there  is  no  organic  or  external  difficulty .  Thus,  we  are 
apt  to  infer  that  one  whom  we  strongly  dislike,  is  a  bad 
man,  because  he  exhibits  some  indication  which  leads  to 
that  conclusion,  though  it  may  really  prove  no  such  thing, 
and  there  may  be  positive  proof  to  the  contrary.  On 
the  other  hand,  we  are  very  ready  to  infer  that  those  we 
like  are  penitent,  moral  or  intelligent,  because  they  have 
done  something  which  faintly  indicates  such  an  infer- 
ence, when  there  may  be  clear  evidence  of  the  reverse. 

To  this  paralogism  belongs  a  host  of  common  errors 
regarding  the  condition  and  character  of  others.  A 
bashful  man  is  often  assumed  to  lack  abilities  or  knowl- 
edge, while  one  who  exhibits  assurance  is  taken  to  be  a 
man  of  talents  and  intelligence.  A  fine  dress  and  equip- 
age have  sometimes  procured  the  credit  of  wealth,  which 
Avas  assumed  to  betoken  happiness.  Such  errors  are 
more  common,  because  the  thing  assumed  to  be  the  sign 
is  often  caused  by  wilful  imposition.  It  is  often  easy  to 
borrow  the  language  of  the  wise,  the  generous  or  the 
learned,  while  those  addressed  never  suspect  the  imposi- 
tion, and  consequently  give  the  impostor  credit  for  what 
really  belongs  to  another.  So  the  felon  often  counter- 
feits signs,  to  remove  suspicion  from  himself,  while  he  re- 
moves the  real  signs  of  his  guilt.  By  such  means,  almost 
every  virtue  has  been  counterfeited,  and  every  vice  at- 
tempted to  be  concealed. 

This  fallacy  is  of  an  insidious  character,  and  very  apt 
to  escape  detection,  because  the  inferences  are  generally 
made  with  such  rapidity  that  we  overlook  them,  and  sup- 


SEC.  4.]    NON-INTERPRETATION  OF  SIGNS,  &c.  273 

pose  that  we  apprehend  what  we  only  infer.  Hence  it 
is  very  apt  to  lead  us  into  further  errors,  because  we  as- 
sume the  false  inference  as  an  unquestionable  compre- 
hension. 

2.  Non-interpretation  of  signs  is  the  converse  o£  the 
preceding  fallacy,  and  occurs  where,  owing  to  careless- 
ness or  prejudices,  we  overlook  the  obvious  and  conclu- 
sive signification  of  a  phenomenon  presented  to  our  view, 
and  thus  form  an  erroneous  opinion  of  the  subject.  A 
common  instance  of  it  is,  where  we  overlook  the  signifi- 
cation of  certain  actions  performed  by  a  person  of  whom 
we  think  favorably,  and  consequently  form  a  better  opin- 
ion of  him  than  his  real  character  warrants.  Another 
similar  instance  is,  when  we  form  too  low  an  opinion  of 
one  whom  we  dislike,  because  we  misinterpret  his  ac- 
tions. 

Paralogisms  of  signs  are  often  combined  with  those 
of  comprehension.  We  obtain  either  an  inaccurate  or 
a  partial  view  of  what  is  presented  to  our  observation, 
and  we  misinterpret  what  we  do  comprehend.  Thus, 
we  are  apt  to  form  erroneous  opinions  regarding  the 
characters  of  nations,  from  that  of  a  few  persons,  with 
whom  we  are  not  well  acquainted,  and  whose  conduct 
we  misunderstand.  So,  if  we  extended  our  acquaintance 
with  the  man  of  supposed  wealth,  we  might  possibly  find 
that  what  procured  him  the  credit  of  wealth  had  never 
been  paid  for :  and  a  further  acquaintance  with  the  man 
who  counterfeited  wisdom  and  virtue,  might  show  him 
to  be  a  silly  knave. 

A  common  and  serious  instance  of  this  compound  fal- 
lacy occurs  in  the  undue  importance  so  frequently  attach- 
ed to  material  interests  and  sensual  enjoyments.  Our 
apprehensions  frequently  show  us  only  the  least  import- 
ant side  of  the  subject :  but  as  this  is  seen  at  once,  we 
are  apt  to  look  no  further,  while,  in  order  to  form  a  cor- 
rect estimate,  we  must  view  the  whole  subject.  This 
often  requires  toil  and  time,  which  we  are  unwilling  to 
bestow,  and  self-denial,  which  we  are  unwilling  to  prac- 
tice. Hence  men  often  form  very  erroneous  opinions, 
and  sacrifice  a  great  good  for  one  of  comparatively  no 
consequence.  In  order  to  form  a  proper  judgement  re- 
garding the  comparative  merits  of  different  things  or 
courses  of  action,  we  must  obtain  a  full  and  fair  view  of 
every  one  of  them ;  and  this  may  be  prevented  by  our 
M2 


2 74  PARALOGISMS.  [CHAP.  XVII. 

prejudices  wholly  withdrawing  the  attention  from  sever- 
al points,  so  that  we  seriously  err  without  ever  suspect- 
ing the  fallacy. 

§  5.  PARALOGISMS  OP  MEMORY. — (1)  Imaginary  Apprehension. — Its 
Origin. — (2)  False  Association. — Its  Character  and  Effects. — (3) 
Mistaking  Ideas. — Its  Character,  and  what  it  particularly  affects. 
— (4)  Forgetf ulness.  — Distinction. 

1.  The  paralogism  of  imaginary  apprehension  consists 
in  confounding  the  remembrance  of  apprehensions  with 
that  of  conceptions,  or  mistaking  a  phantasm  for  an  idea, 
whence  we  think  that  we  apprehended  what  we  only  im- 
agined.    We  fall  into  this  error  only  when  our  remem- 
brance of  an  occurrence  is  indistinct  or  defective  :  for,  in 
other  cases,  the  remembrance  of  the  circumstances  under 
which  the  conception  was  formed,  will  prevent  any  such 
mistakes.     It  occurs  chiefly  where  some  favorite  concep- 
tion has  been  often  considered,  or  originally  absorbed 
the  attention  to  such  a  degree  that  the  impressions  made 
by  other  things  were  faint,  and  consequently  they  have 
been  forgotten,  while  the  remembrance  of  the  conception 
is,  for  the  same  reason,  unusually  vivid.     It  is  owing  to 
this  fallacy  that  we  hear  some  old  men  relating,  with  per- 
fect sincerity,  that  they  saw  or  performed  things  which 
are  purely  imaginary. 

2.  False  association  occurs  where  we  mistake  the  time 
or  place  of  apprehending  a  certain  thing.    This  is  owing 
chiefly  to  the  idea  of  one  apprehension  becoming  asso- 
ciated with  that  of  another  which  was  not  contempora- 
neous with  it,  whence  we  infer  that  the  two  prototypes 
were  simultaneous.     Thus,  we  often  believe  that  we  saw 
an  acquaintance  at  a  particular  time  or  place,  when,  in 
fact,  we  saw  him  at  another  time  or  elsewhere.     Such 
mistakes  are  of  frequent  occurrence,  and  sometimes  pro- 
duce serious  consequences. 

3.  Mistaking  ideas  is  where  the  idea  of  one  apprehen- 
sion is  mistaken  for  that  of  another,  owing  to  indistinct- 
ness or  failure  of  remembrance,  whence  we  believe  that 
we  apprehended  a  thing  when  we  apprehended  only 
something  like  it.    This  fallacy  closely  resembles  that  of 
miscomprehension,  writh  which  it  is  frequently  combined, 
owing  to  our  employing  ideas  as  representatives  of  their 
prototypes.     It  affects  number  and  quantity  so  much 
that  little  dependence  can  be  placed  on  the  remembrance 


SEC.  6.]  FORGETFULNESS,  &c.  275 

of  ji  person  of  ordinary  memory,  regarding  such  things, 
except  where  his  attention  was  particularly  directed  to 
them,  at  the  time  of  apprehension. 

4.  Forgetfulness  is  where  we  wholly  forget  something, 
and  then  assume  that  'we  never  comprehended  it.  As 
we  are  liable  to  such  forgetfulness,  the  mere  fact  that  we 
have  no  recollection  of  a  thing,  does  not  prove  that  we 
never  comprehended  it.  Hence  the  only  safe  inference 
is,  that  we  do  not  remember  it,  except  it  be  such  that  we 
could  not  possibly  forget  it,  if  once  comprehended.  But 
this  condition  is  often  overlooked,  and  we  think  that  we 
never  comprehended,  when  we  only  forget.  This  fallacy 
is  frequently  combined  with  those  of  comprehension,  as 
we  are  very  apt  to  forget  what  we  never  rightly  compre- 
hended. Instances  of  it  occur  where  we  undertake  to 
do  something  in  utter  forgetfulness  of  the  fact  that  we 
have  already  done  it.  Another  similar  instance  is,  when 
we  believe  that  we  never  saw  or  said  something  which 
we  really  did,  because  we  have  no  recollection  of  having 
done  so. 

Memory  generally  retains  the  errors  of  original  com- 
prehension. Thus,  if  we  mistook  the  character  of  a  thing 
when  we  saw  it,  without  discovering  our  error,  we  shall 
continue  to  think  that  we  saw  what  we  took  it  to  be, 
unless  extraneous  circumstances  show  that  we  were  mis- 
taken :  but  neither  the  error  nor  the  correction  proceeds 
from  the  Memory ;  and  hence  the  consideration  of  them 
does  not  concern  our  present  subject. 

§  6.  INTRINSIC  PARALOGISMS  or  TESTIMONY. — Immaterial  Distinc- 
tion.— Intrinsic  and  Extrinsic  Paralogisms  of  Testimony. — (1)  Am- 
biguous Expression .  — Logom  achies.  — Equivocation . — Ambiguous 
Interrogation.  —  (2)  Overlooking  Conditions.  — Results. — (3)  As- 
suming Conditions. — (4)  Obscure  Expression. — Frequent  source  of 
this  Fallacy. — Proper  mode  of  dealing  with  it. — (5)  Wrong  Ex- 
pression.— (6)  Falsehood. — Its  Extent. — Erroneous  Definitions. — 
(7)  Suppressing  Truth. — Where  to  be  expected. — (8)  Misrepresent- 
ing Comprehensions. — Its  Extent. — (9)  Misrepresenting  Testimo- 
ny.— Where  frequently  employed.— Frequent  Combinations. 

The  question  whether  a  witness  believes  his  own  state- 
ments or  not',  is  of  the  utmost  importance  when  we  are 
considering  his  character:  but  it  is  generally  of  little  or 
no  consequence  when  we  are  inquiring  whether  they  are 
true  or  false.  The  real  sincerity  of  a  witness  who  be- 
lieves his  false  statements,  is  quite  as  apt  to  mislead  us 


276  PARALOGISMS.  [CiiAi*.  XVJI. 

as  the  mock  sincerity  of  the  liar ;  and  the  belief  or  dis- 
belief of  the  witness  is  frequently  no  test  of  truth.  Men 
often  hear  and  relate  truth  without  believing  it;  and  they 
still  more  frequently  utter  falsehood  unawares.  Conse- 
quently we  shall  not  here  draw  any  distinction  between 
conscious  and  unconscious  errors.  The  character  of  the 
fallacy  is  generally  unaffected  by  the  belief  or  disbelief, 
of  the  witness. 

Paralogisms  of  testimony  are  either  intrinsic  or  ex- 
trinsic. The  former  comprise  those  where  the  testimo- 
ny is  fallacious  in  itself:  the  latter  include  those  which 
arise  from  our  dealing  with  it  fallaciously.  We  shall 
treat  of  the  former  in  this,  and  of  the  latter,  in  the  ensu- 
ing section. 

1.  Expressions  bear  two  or  more  different  significa- 
tions, which  are  not  distinguished,  constituting  the  pa- 
ralogism of  ambiguous  expression.  Thus,  "  testimony  is 
fallacious,"  may  signify  all  or  only  some  testimony.  All, 
again,  may  signify  either  every  one  separately  or  the 
whole  together  ;  and  some  may  denote  a  very  few  or  a 
great  many.  So,  "  a  scriptural  custom"  may  signify  sim- 
ply one  which  is  frequently  referred  to  in  the  Scriptures 
as  existing,  without  any  expression  of  approval;  or  it 
may  signify  one  which  is  described  as  having  the  divine 
sanction,  which  is  a  very  different  thing. 

Many  logomachies  arise  from  overlooking  the  ambigu- 
ity of  expressions.  Such  questions  as  "  who  was  the 
greatest  man  that  ever  lived  ?"  can  be  only  disputes 
about  words,  till  the  parties  have  agreed  in  which  of  its 
numerous  significations  the  word  great  is  to  be  under- 
stood. In  all  such  cases,  there  are,  in  reality,  as  many 
different  questions  as  there  are  different  significations  of 
the  expressions  used. 

A  common  instance  of  this  paralogism  is,  equivocation, 
or  employing  expressions  which  are  true  in  one  sense, 
but  not  in  another,  while  the  witness  furnishes  no  indi- 
cation which  of  the  two  he  would  have  us  adopt.  Some- 
times we  cannot  ascertain  whether  the  language  is  fig- 
urative or  literal,  as  when  commendatory  epithets  are 
used,  and  they  may  possibly  be  ironical.  This  proceeds 
sometimes  from  a  design  to  mislead,  and  at  other  times, 
from  mere  inattention  or  oversight.  The  ancient  hea- 
then oracles,  and  the  ambiguities  purposely  used  in  mak- 
ing contracts,  furnish  many  instances  of  the  former,  and 
hasty  compositions,  of  the  latter. 


SEC.  6.J  FALLACIOUS  EXPRESSIONS.  277 

Sometimes  the  ambiguity  assumes  the  form  of  an  in- 
terrogation, which  appears  to  admit  of  only  one  answer, 
but,  in  reality,  admits  of  several,  some  true  and  some 
false.  This  form  is  distinguished  as  ambiguous  interro- 
gation. It  is  frequently  employed  by  witnesses  who  are 
unwilling  to  make  a  direct  misstatemept,  which  they  at- 
tempt to  avoid  by  an  apparently  candid  appeal  to  the  in- 
terrogator, as  if  the  answer  sought  must  be  obvious  to 
himself.  The  fallacy  lies  in  the  ambiguity  of  the  ques- 
tion, and  is  to  be  avoided  by  ascertaining  which  of  the 
several  significations  is  meant. 

2.  Expressions  which  are  true  only  on  certain  condi- 
tions, are  stated  as  if  they  were  true  absolutely,  forming 
the  paralogism  of  overlooking  conditions.     When  it  is 
said  that  "  a  man  can  live  without  eating  on  Saturday," 
this  may  be  true  if  he  did  not  fast  before,  but  very  false, 
if  he  has  fasted  during  the  previous  fortnight.     This  pa- 
ralogism is  one  of  the  principal  means  of  riveting  the 
numerous  errors  arising  from  partial  views  of  a  subject. 
The  language  employed  may  directly  express  nothing 
but  what  is  strictly  true ;  yet  it  naturally  implies  some- 
thing which  is  false.     An  ancient  author  might   say: 
"  the  Sun  appears  in  the  south  at  noon,  in  every  part  of 
the  known  world,"  and  the  statement  would  be  strictly 
true ;  but  the  same  expression  is  quite  false  at  the  pres- 
ent day. 

3.  Expressions  which  are  true  absolutely,  are  assumed 
to  be  true  only  on  certain  conditions,  forming  the  paral- 
ogism of  assuming  conditions.     A  common  instance  of 
it  is,  where  a  man  assumes  that  some  substance,  habit, 
or  course  of  life,  will  not  injure  him,  on  account  of  his 
peculiar  constitutional  character,  when,  in  fact,  it  inevi- 
tably injures  every  one,  just  as  fire  burns,  or  ice  chills. 

4.  The  expressions  are  so  obscure  that  it  is  impossible 
to  ascertain  their  precise  meaning,  or  whether  they  have 
any,  forming  the  paralogism  of  obscure  expression.    A 
common  instance  of  it  is,  using  figurative  language  in 
such  a  manner  that  we  cannot  form  any  definite  notion 
of  its  meaning,  whence  we  are  liable  to  misunderstand 
it.     The  proper  course,  in  such  cases,  is,  to  attach  no 
meaning  whatever  to  the  language:  for  otherwise  we 
shall  very  probably  attribute  to  it  a  meaning  different 
from  what  was  intended. 

5.  Wrong  expression  is  where  a  person  employs  words 


278  PARALOGISMS.  [CHAP.  XVII. 

which  may  be  suiBciently  clear  and  precise,  but  yet  con- 
vey a  meaning  different  from  what  he  intended.  Some- 
times improper  terms  are  employed :  in  other  cases,  they 
are  unobjectionable,  but  they  are  wrongly  arranged  or 
constructed.  Typographical  blunders,  and  slips  of  the 
tongue,  furnish  numerous  instances  of  both  these  forms. 

6.  Falsehood  is,  where  a  person,  either  knowingly  or 
otherwise,  makes  a  statement  which  is  substantially,  if 
not  wholly,  untrue,  with  the  expectation  of  being  be- 
lieved.    Many  expressions  are  false,  in  their  ordinary  ac- 
ceptation, which  do  not  come  under  this  head,  because 
the  real  meaning  is  well  understood,  as  in  the  case  of 
figures  of  speech  ;  but  here  the  witness  speaks  with  the 
intention  of  producing  belief;  and  the  difficulty  general- 
ly lies  in  the  fact  that  there  is  no  clear  indication  of  the 
misstatement.     It  is  frequently  believed,  owing  to  the 
apparent  veracity  and  sincerity  of  the  witness,  the  small- 
ness  of  the  temptation  to  depart  from  truth,  or  the  indo- 
lence or  prejudices  of  the  party  addressed.     It  is  also 
of  very  common  occurrence,  because  there  are  so  many 
ways  of  being  mistaken,  and  so  many  temptations  to 
misrepresent,  even  where  the  witness  is  well  aware  of 
the  truth. 

A  pernicious  instance  of  this  paralogism  is,  false  defi- 
nition. This  is  very  apt  to  escape  detection,  owing  to 
the  ignorance  of  the  party  addressed,  and  the  presump- 
tion that  he  who  undertakes  to  give  a  formal  definition 
of  a  thing,  understands  it  well.  As  definitions  affect 
fundamental  points,  errors  of  this  kind  are  very  apt  to 
convey  radically  erroneous  views  of  the  whole  subject. 

7.  Suppressing  truth  is  where  an  important  part  of  the 
testimony,  or  of  what  was  witnessed,  is  entirely  omitted, 
or  the  facts  are  garbled,  and  the  favorable  or  unfavora- 
ble alone  stated.     A  frequent  instance  of  it  is,  depicting 
a  few  individuals  of  a  class  as  fair  specimens  of  the  whole, 
when,  in  reality,  they  are  not.     This  may  not  be  directly 
stated ;  but  things  are  represented  so  as  to  lead  to  that 
inference.     Every  large  class  generally  contains  persons 
of  very  different  characters ;  and  it  is  easy  to  select  a 
few  that  differ  widely  from  the  great  majority,  who  alone 
determine  the  character  of  the  class.     By  such  means 
very  different  pictures  may  be  exhibited  of  the  same 
community,  the  one  as  much  darker  than  the  reality  as 
the  other  is  brighter.     So,  by  selecting  the  good  and  bad 


SEC.  6.]  MISREPRESENTATION.  279 

qualities  of  an  individual,  two  very  erroneous  exhibitions 
may  be  easily  given  of  his  character,  yet  both  containing 
some  portion  of  truth,  so  that  they  are  readily  received 
as  accurate  by  those  who  like  them. 

8.  Misrepresenting  comprehensions  occurs  where  the 
truth  is  either  exaggerated,  extenuated,  or  mixed  with 
more  or  less  of  positive  error,  in  a  statement  of  what  the 
witness  personally  observed  or  experienced.     This  is  oft- 
en done  by  employing  terms  either  weaker  or  stronger 
than  truth  requires.     Many  actions  or  characters  may  be 
viewed  jn  a  favorable  or  an  vftifavorable  light,  as  several 
virtues  border  on  corresponding  vices;   and  language 
affords  abundant  means  of  representing  it  under  either 
aspect,  so  as  to  contain  some  portion  of  truth. 

Hence  there  is  a  boundless  field  for  the  exercise  of  this 
paralogism.  Penurious  selfishness  may  be  dignified  un- 
der the  name  of  "  a  prudent  regard  to  our  own  interests," 
while  a  proper  degree  of  economy  may  be  styled  "  nig- 
gardly parsimony."  Indifference  to  the  welfare  of  others 
often  passes  for  "  good  nature,"  while  one  who  warns  us 
of  serious  danger,  which  we  .wish  to  overlook,  is  termed 
"an  officious  intermeddler,"  and  a  well-timed  rebuke 
passes  for  "  scolding."  An  action  may  be  called  V  brave" 
or  "  rash" — "  prudent"  or  "  cowardly" — "  energetic"  or 
"  severe" — "  liberal"  or  "  extravagant."  Real  sublimity 
may  be  termed  "  unmeaning  rant,"  while  bombast  passes 
for  "  sublimity."  Vapid  declamation  is  termed  "  true 
oratory,"  while  genuine  eloquence  is  characterized  as 
"  tumid  bombast."  Ruling  a  nation  with  a  rod  of  iron 
has  sometimes  been  termed  "  administering  the  govern- 
ment with  a  strong  hand,"  while  inefficient  imbecility 
was  styled  "  rnild  and  paternal  sway." 

Instances  of  this  fallacy  occur  in  the  justificatory  or 
defensive  .statements  of  a  party  charged  with  having 
done  something  wrong ;  and  its  influence  may  often  be 
readily  seen  by  comparing  the  narratives  which  two  ad- 
verse parties  give  of  the  same  occurrence. 

9.  Misrepresenting  testimony  is,  where  reliable  testi- 
mony is  misrepresented,  so  as  to  corrupt  it  materially. 
This  is  done  in  various  ways.     Sometimes  it  is  mistrans- 
lated ;  and  the  error  often  escapes  detection,  owing  to 
the  original  being  unknown  or  inaccessible  to  the  party 
addressed.     Sometimes  it  is  misquoted,  and  various  gar- 
bled passages  are  strung  together,  with  some  important 


280  PARALOGISMS.  [CHAP.  XVII. 

additions  or  alterations,  so  as  to  convey  a  meaning  very 
different  from  the  original.  At  other  times  confident  ref- 
erences are  made  to  testimony,  as  proving  a  certain  prop- 
osition which  it  does  not  prove,  sometimes  with  the  ex- 
pectation that  it  will  never  be  consulted  by  the  party 
addressed ;  and  the  fallacy  is  occasionally  masked  by  a 
bold  statement  that  the  testimony  is  clear  and  conclusive, 
while  possibly  it  may  be  all  the  other  way. 

This  paralogism  is  of  frequent  occurrence  in  contro- 
versy. An  opponent's  views  are  misrepresented,  and 
then  follows  a  refutation  of  imaginary  statements  or  opin- 
ions ;  or  the  doctrines  of  a  party  are  erroneously  assumed 
to  be  the  same  as  those  of  some  person  connected  with 
it.  Fallacies  of  this  kind  occur  so  frequently  that  little 
confidence  can  generally  be  placed  in  a  professed  contro- 
versialist's representations  of  an  opponent's  views,  except 
where  he  quotes  fairly  from  some  unexceptionable  au- 
thority ;  and  it  is  unsafe  to  assume  that  he  does  so,  with- 
out proof. 

The  two  paralogisms  of  misrepresentation  are  most 
frequently  couched  in  spoken  or  written  language:  but 
they  are  sometimes  communicated  by  various  other 
means,  such  as  inaccurate  maps  or  pictures,  or  by  sounds 
and  tastes  or  odors,  which  do  not  rightly  represent  what 
they  profess  to  do,  as  if  a  man  should  present  an  apple,  to 
give  us  a  notion  of  the  smell  of  a  rose,  or  imitate  the  note 
of  the  raven,  as  a  correct  representation  of  the  cuckoo's. 

Intrinsic  fallacies  of  testimony  are  frequently  combined 
with  each  other.  Ambiguous,  obscure  or  wrong  expres- 
sions accompany  and  strengthen  falsehood,  suppression 
and  misrepresentation,  so  that  it  is  sometimes  very  diffi- 
cult to  ascertain  their  true  character.  This  can  be  done 
only  by  a  close  and  careful  application  of  the  criterions 
of  testimony,  \vhich  frequently  requires  time  and  toil, 
while  the  adoption  of  the  fallacy  requires  neither.  Hence 
they  have  been  a  very  frequent  and  powerful  means  of 
producing  and  perpetuating  error. 

§  7.  EXTRINSIC  PARALOGISMS  or  TESTIMONY. — (1)  Adopting  a  Mean. 
— Erroneous  Assumption. — (2)  Counting  Witnesses. — Relation  of 
Numbers  to  Credibility.  — (3)  Credulity.  — Why  prevalent.  — (4) 
Scepticism. — Its  Origin  and  Operation. — (5)  Overlooking  Testi- 
mony.— Its  Origin. — (6)  Indiscrimination. — Why  prevalent. — Fre- 
quent Combinations. 

1.  Adopting  a  mean  is,  where  there  are  contradictory 


SEC.  7.]  ABUSES  OF  TESTIMONY.  281 

or  inconsistent  testimonies,  and  we  assume  that  the  truth 
lies  between  the  statements  of  the  different  parties,  Avhile 
it  may  be  quite  otherwise.  It  is  so  much  easier  to  ap- 
portion the  difference  between  conflicting  testimonies 
than  to  ascertain  their  true  character,  that  this  fallacy  is 
of  frequent  occurrence. 

Some  persons  generally  assume,  in  all  cases  of  this 
kind,  where  their  prejudices  are  not  concerned,  that  the 
truth  lies  somewhere  between  the  assertions  of  the  dif- 
ferent parties ;  and  they  take  it  to  be  nearest  to  those  of 
the  one  who  speaks  with  most  confidence,  whereas  it  is 
often  beyond  the  statements  of  either  party,  or  wholly 
with  one,  and  that  the  party  who  speaks  with  least  con- 
fidence ;  and  we  can  never  safely  assume  that  it  is  inter- 
mediate without  conclusive  proof. 

Wherever  the  statements  are  not  only  inconsistent,  but 
contradictory,  the  truth  cannot  by  possibility  lie  between. 
If  one  says  CaBsar  was  a  tyrant,  and  the  other  says  he 
was  not,  one  must  be  wholly  right  and  the  other  equally 
wrong.  It  is  also  evident  that  there  is  never  any  rational 
and  tenable  mean  between  truth  and  falsehood.  If  the 
creed  of  the  theist  is  true,  that  of  the  atheist  must  be 
quite  false :  and  if  the  peculiar  doctrines  of  the  Trinita- 
rian are  true,  those  of  the  Ariau  must  be  as  erroneous  as 
the  Socinian's. 

2.  Counting  witnesses  occurs  where  the  testimony  is 
estimated  by  the  number  of  the  witnesses,  regardless  of 
their  character,  the  many  being  thought  entitled  to  much, 
and  the  few,  to  little  credit.     A  frequent  instance  is,  the 
credit  given  to  common  rumor,  where,  as  is  usually  the 
case,  its  origin,  and  consequently  its  value,  are  unknown. 
The  prevalence  of  this  practice  is  shown  by  the  proverb, 
"  what  everybody  says  must  be  true" — the  predicate 
meaning  simply  general  report,  which  is  often  quite  false. 
Testimonies  should  be  weighed,  not  counted ;  and  conse- 
quently all  those  which  have  no  weight,  ought  to  go  for 
nothing.     One  unexceptionable  witness  is  entitled  to  im- 
plicit belief,  while  one  million  of  worthless  witnesses  are 
entitled  to  none.     But  as  counting  is,  in  this  case,  a  much 
easier  process  than  weighing,  it  is  often  adopted. 

3.  The  paralogism  of  credulity  occurs  where  we  receive 
as  'satisfactory,  testimony  which  is  palpably  unreliable, 
and  which  we  could  very  readily  perceive  to  be  such,  by 
a  moment's  consideration.     This  fallacy  is  very  preva- 


282  PARALOGISMS.  [CHAP.  XVII. 

lent,  because  it  is  fostered  by  several  strong  prejudices. 
The  "  Mississippi  System"  of  Law,  in  France,  and  the 
"  South  Sea  Scheme"  of  Blount,  in  England,  which  caused 
such  wide-spread  ruin,  in  the  early  part  of  the  eighteenth 
century,  are  two  notable  instances  of  this  kind.  Other 
instances  occur  in  the  ready  belief  given  to  the  hyperbol- 
ical exaggerations  of  partisans. 

4.  Scepticism  is,  where  testimony  which  might  be  easi- 
ly ascertained  to  be  conclusive,  is  rejected  as  unsatisfac- 
tory.    This  fallacy  is  simply  the  converse  of  the  preced- 
ing, and  has  a  similar  origin.     Hence  both  are  often 
adopted  by  the  same  person,  in  reference  to  the  same  sub- 
ject.   The  favorable  testimony  is  believed,  though  worth- 
less, and  the  unfavorable  is  rejected,  though  conclusive. 
Instances  occur  in  the  frequent  rejection,  by  many,  of  sci- 
entific truths,  established  by  evidence  of  which  they  could 
easily  ascertain  the  conclusiveness. 

5.  We  either  wholly  overlook,  or  pass  by  without  any 
serious  attention,  accessible  testimony  which  materially 
affects  the  point  under  consideration,  and  assume  that 
we  have  properly  considered  all  the  testimony,  forming 
the  paralogism  of  overlooking  testimony.     This  fallacy 
naturally  flows  from  the  disagreeableness  of  a  long  inves- 
tigation of  evidence ;  and  hence  it  is  of  frequent  occur- 
rence.    We  have  a  common  instance  in  the  errors  into 
which  many  historians  have  been  led,  by  failing  to  con- 
sult important  testimonies  within  their  reach. 

6.  Indiscrimination  is  where  we  either  receive  the 
whole  of  a  testimony  as  satisfactory,  because  some  parts 
of  it  are  so,  or  reject  it  all  as  incredible,  for  a  similar  rea- 
son.    The  most  faithful  witness  sometimes  makes  slight 
mistakes  himself,  or  is  misled  by  others,  in  matters  of  lit- 
tle moment,  while  his  testimony  may  be,  very  correct,  in 
the  main.    On  the  other  hand,  the  least  credible  witness 
generally  relates  some  portion  of  the  truth,  even  where 
his  statements  are  substantially  false.    Yet,  as  it  is  much 
easier  to  accept  or  reject  in  the  mass  than  to  sift  out 
truth  from  error,  this  fallacy  is  very  prevalent. 

The  paralogisms  described  in  this  section  are  frequent- 
ly combined  with  those  of  comprehension  and  other  fal- 
lacies of  testimony,  a  combination  which  often  produces 
unhesitating  conviction. 


SEC.  8.]  MISINTERPRETATION.  283 

§  8.  PARALOGISMS  OF  MISINTERPRETATION  OF  LANGUAGE. — Nature 
and  Origin  of  this  class  of  Paralogisms. — (1)  Misunderstanding 
Archaisms. — (2)  Misinterpreting  Technicalities. — (3)  Misinterpret- 
ing Ambiguities. — (4)  Confounding  different  senses.  —  (5)  Over- 
looking the  Idiom. — (6)  Following  Etymologies. — (7)  Mistaking 
the  Style.  —  (8)  Misplacing  the  Accent. — (9)  Misconstruction. — 
(10)  Mistaking  Expressions. — Its  Sources  and  Effects. — (11)  Igno- 
rant Interpretation. — Its  Origin. — (12)  Misconception. — Frequent 
source  of  it. — (13)  Fallacious  Implication. — (14)  Mistaking  Allu- 
sions.— Where  frequent.  —  (15)  Fallacious  Propriety.  — Why  fre- 
quent.— Effects  of  these  Paralogisms. 

This  class  of  fallacies  comprises  those  cases  in  which 
we  misunderstand  or  misinterpret  statements  which  may 
be  perfectly  fair  and  correct  in  themselves.  They  pro- 
ceed from  the  defects  of  language,  ignorance,  careless- 
ness, or  prejudice.  The  following  enumeration  includes 
the  most  common : 

1.  We  affix  to  a  term  its  ordinary  signification  at  the 
present  day,  when,  in  reality,  it  is  used  in  an  antiquated 
sense,  which  we  may  term  misunderstanding  archaisms. 
It  is  apt  to  occur  in  interpreting  ancient  laws,  or  other 
compositions  of  a  remote  period,  as  where  the  word 
"publish"  is  taken  to  signify  print  and  off er  for  sale, 
while  it  means  to  utter  or  proclaim  in  public,  or  where 
to  "prevent"  is  interpreted  to  keep  back,  when  it  means 
to  go  before. 

2.  We  overlook  the  nature  of  the  composition,  and  in- 
terpret words  in  their  ordinary  sense,  when  they  are 
used  technically,  or  conversely,  which  may  be  termed 
misinterpreting  technicalities.     By  a  gale  a  seaman  un- 
derstands a  high,  strong  wind,  while,  in  ordinary  lan- 
guage it  means  only  a  moderate  breeze. 

3.  Misinterpreting  ambiguities  is  where  we  attach  to 
an  ambiguous  expression  a  sense  different  from  what  was 
intended.     This  we  are  very  apt  to  do  where  we  know 
little  of  the  subject  or  the  language,  and  consequently 
misunderstand  the  context.     Many  instances  occur  in  va- 
rious interpretations  affixed  by  commentators  to  ambig- 
uous passages  in  ancient  authors. 

4.  Confounding  different  senses  is  where  we  blend  va- 
rious significations  of  an  expression,  and  unconsciously 
understand  it  now  in  one  sense,  and  then  in  another,  so 
that  we  form  a  confused  conception  of  its  import.     The 
various  confused  significations  attributed  to  such  words 
as  law,  idea,  and  nature,  are  instances  of  this  fallacy. 


284  PARALOGISMS.  [CHAP.  XVII. 

5.  Overlooking  the  idiom  occurs  where  we  attribute 
to  a  foreign  expression  the  exact  import  of  the  corre- 
sponding words  in  our  vernacular,  while  there  are  im- 
portant differences  in  their  significations.     This  is  apt  to 
occur  where  our  knowledge  of  the  idiom  is  imperfect, 
and  we  are  not  well  acquainted  with  the  history,  institu- 
tions and  manners  of  the  people  whose  language  we  in- 
terpret.     Virtus,  in  old  Roman  authors,  does  not  gener- 
ally mean  virtue,  but  valor  ;  temperantia  meant  modera- 
tion in  desires  and  pursuits,  as  well  as  in  eating  and 
drinking,  while  humilitas  denoted  abjectness  or  mean- 
ness, a  very  different  thing  from  what  we  now  under- 
stand by  humility. 

6.  Following  etymologies  is  where  we  assume  that  a 
derivative  or  compound  term  has  the  exact  signification 
of  its  original,  when,  in  fact,  they  mean  things  widely 
different.     This  fallacy  is  of  frequent  occurrence  in  in- 
terpreting dead  languages,  where  too  much  importance 
is  often  attached  to  etymology,  owing  to  our  other  means 
of  ascertaining  its  signification  being  very  scanty.     We 
often  trow  things  that  are  not  true;  we  may  form  JOTO/- 
ects  or  speculations  without  being  projectors  or  speculat- 
ors ;  and  we  are  not  bound  to  observe  a  holiday  as  a 
holy  day. 

7.  Mistaking  the  style  occurs  where  that  which  is  fig- 
urative is  interpreted  literally,  or  conversely.     Such  er- 
rors readily  spring  from  overlooking  the  nature  of  the 
subject,  or  the  differences  between  the  style  of  one  lan- 
guage  and   another.     Some   languages   employ  figures 
more  freely  than  others ;  and  hardly  any  two  use  them 
precisely  alike,  in  all  cases.     A  common  instance  of  this 
fallacy  is,  where  figurative  idiomatic  phrases  are  taken 
in  their  literal  acceptation.     Such  expressions  as  "  a  man 
beside  himself,"  or  "  out  of  his  mind,"  puzzle  persons  ig- 
norant of  the  English  idiom,  while  the  corresponding  ex- 
pressions in  their  languages  may  be  equally  obscure  to 
all  those  who  are  not  familiar  with  them. 

8.  Misplacing  the  accent  is,  where  we  attach  a  wrong 
meaning  to  an  expression  from  mistaking  the  accented 
word.     The  proposition  "  he  who  sins  shall  die,"  points 
out  either  the  subject  or  the  nature  of  the  retribution, 
according  as  we  accent  the  subject  or  the  predicate.     So 
if  only  the  last  word  of  the  ninth  commandment  be  ac- 
cented, it  is  made  to  forbid  belying  only  our  neighbours. 


SEC.  8.]  MISINTERPRETATION.  285 

9.  Misconstruction  is  where  some  word  is  assumed  to 
qualify  the  wrong  term,  the  true  construction  being  mis- 
understood.    This  fallacy  abounds  in  translations.     The 
expression  Aio  te  Romanos  vincere  posse,  may  be  ren- 
dered "  I  say  that  thou  canst  conquer  the  Romans," — 
or  "  I  say  that  the  Romans  can  conquer  thee."     So  redi- 
bis  nunquam  peribis,  signifies  "  thou  shalt  return  ;  thou 
shalt  never  perish" — or  "  thou  shalt  never  return  ;  thou 
shalt  perish" — according  as  we  assume  the  pause  before 
or  after  nunquam. 

10.  Mistaking  expressions  occurs  where  we  mistake 
the  language  employed,  and  assume  that  something  has 
been  uttered  essentially  different  from  the  reality.     We 
are  very  liable  to  adopt  this  fallacy,  where  the  expres- 
sion is  strange  to  us,  and  yet  resembles  one  with  which 
we  are  familiar.     Many  popular  and  typographical  er- 
rors originate  in  this  way,  as — sparrow  grass  for  aspara- 
gus, animals  for  mammals,  Candia  for  Cardia,  and  Per- 
sians for  Pier ians.     Sometimes  the  negative  particle  is 
overlooked ;  and  thus  a  meaning  is  assumed  the  direct 
contrary  of  what  was  intended.     This  paralogism  has 
caused  various  slanders  and  bitter  quarrels. 

11.  Owing  to  mere  ignorance  of  the  language,  we  at- 
tach to  an  expression  a  meaning  which  it  does  not  bear, 
forming  the  fallacy  of  ignorant  interpretation.     It  arises 
chiefly  from  mistaking  a  term  for  another  which  it  re- 
sembles, or  adopting  the  first  definition  given  in  a  dic- 
tionary.    Many  errors  found  in  translations  have  origin- 
ated in  this  way.     In  various  translations  of  Exodus, 
Chapter  xxxiv.,  verse  7,  one  part  is  rendered  so  as  to 
contradict,  not  only  the  whole  tenor  of  Scripture,  but  the 
immediate  context. 

12.  Misconception  is,  where  we  comprehend  only  a 
part  of  the  meaning  of  an  expression,  and  unconsciously 
miss  what  is  possibly  the  most  important  part.     This 
fallacy  frequently  prevents  truth  from  producing  it's  le- 
gitimate effects  on  the  mind,  because  that  which  is  most 
effectual  continues  unknown,  while  the  individual  believes 
he  understands  the  whole  subject.     The  meaning  attach- 
ed to  many  terms, — such  as  patriotism,  benevolence,  hu- 
mility, justice,  modesty,  and  bravery — depends  greatly  on 
the  character  of  the  party  addressed,'  so  that  four  per- 
sons may  receive  as  many  different  impressions  from  the 
same  term.     In  order  to  comprehend  the  force  and  sig- 


286  PARALOGISMS.  [CHAP.  XVII. 

nificance  of  another's  language,  we  must  frequently,  not 
only  attend  to  his  circumstances,  but  also  enter  into  his 
feelings.  It  is  for  this  reason  that  persons  of  different 
characters  and  principles  so  often  misunderstand,  and 
consequently  misrepresent,  each  other. 

A  frequent  instance  of  this  fallacy  is,  where,  in  reading 
History  or  Biography,  we  attribute  to  the  language  the 
same  signification  which  it  would  bear,  if  used  by  a  con- 
temporary countryman  of  our  own,  when  its  real  signifi- 
cation is  widely  different. 

13.  Fallacious  implication  is,  where  we  assume  that 
the  words  imply  something  which,  in  reality,  they  do 
not.     This  is  apt  to  occur  where  we  are  not  well  ac- 
quainted with  the  subject  or  the  character  of  the  author. 
A  pernicious  instance  of  it  is,  where  the  erroneous  lan- 

Siage  of  men,  recorded  in  Holy  Writ,  is  attributed  to 
od,  and  thus  fallaciously  inferred  to  be  true. 

14.  Mistaking  allusions  is,  where  we  assume  that  the 
speaker  or  writer  alludes  to  one  thing  when,  in  reality, 
he  alludes  to  another.     This  fallacy  is  of  frequent  occur- 
rence in  interpreting  ancient  and  foreign  languages,  as 
we  are  apt  to  overlook  the  differences  between  ancient 
times  or  foreign  countries  and  our  own.     Commentaries 
on  ancient  authors  furnish  many  instances  of  this  paralo- 
gism. 

15.  Fallacious  propriety  is,  where  we  force  on  the  lan- 
guage an  erroneous  meaning,  because  we  think  it  must 
have  been  the  one  intended,  as,  otherwise,  the  sense  con- 
veyed would,  in  our  opinion,  be  false  or  improper.     The 
sense  intended  to  be  conveyed  may  be  untrue  or  improp- 
er, or  we  may  think  so  when  it  is  otherwise,  because  our 
views  of  the  subject  may  be  erroneous  or  defective.     In- 
stances of  this  fallacy  occur  in  the  false  glosses  and  mis- 
interpretations of  Scripture  arising  from  the  erroneous 
assumption  that  any  other  interpretation  would  give  a 
false  or  improper  sense. 

As  we  are  generally  unwilling  to  believe  that  our  own 
views  are  wrong,  and  always  desirous  of  finding  them 
tally  with  those  of  men  whom  we  respect,  this  fallacy  is 
of  frequent  occurrence. 

Fallacies  of  misinterpretation  are  apt  to  be  very  per- 
nicious in  their  effects,  because  they  frequently  refer  to 
subjects  of  great  importance,  while  their  existence  is  un- 
suspected by  their  victims.  Not  only  is  language  an  ini- 


SEC.  1.]  SOPHISMS  OF  CONFUSION.  287 

perfect  weapon  wielded  by  an  arm  which  is  ever  liable 
to  miss  its  aim,  but  its  heaviest  and  most  direct  blows 
are  often  parried  by  carelessness,  ignorance,  prejudice,  or 
stolidity. 


CHAPTER  XVIII. 

OF   SOPHISMS,  OR   FALLACIES    OF   INTERMEDIATE   REASON- 
ING. 

§  1.  SOPHISMS  OP  CONFUSION. — Nature  of  this  class  of  Fallacies. — 
(1)  Sophistical  Connection. —  Eelations  of  Conclusions  and  Pre- 
mises.— Influence  of  Prejudices. — .(2)  Inferring  the  Converse. — 
Why  it  often  escapes  detection. — Relations  of  a  Proposition  to  its 
Converse. — (3)  Altering  Propositions. — How  sometimes  disguised. 

THIS  class  of  fallacies  comprises  those  cases  in  which 
we  draw  inferences  not  implied  in  our  premises,  owing 
to  our  mistaking  one  proposition  for  another  which  re- 
sembles it,  but  is  yet  essential  different.  The  following 
are  the  principal  kinds  : 

1.  Sophistical  connection  is,  where  premises  are  as- 
sumed to  be  true  or  false,  according  to  our  opinio.n  of 
the  conclusion  deduced  from  them ;  or,  conversely,  the 
conclusion  is  assumed  to  be  true  or  false,  according  as  it 
is  implied  in  the  premises  or  not. 

False  premises  are  often  employed  to  prove  true  con- 
clusions, and  unobjectionable  premises  are  often  employ- 
ed to  prove  false  conclusions,  while  false  conclusions  may 
be  implied  in  false  premises.  The  premises  and  the  con- 
clusion, again,  may  be  both  true,  while  the  latter  is  not 
implied  in  the  former :  but  the  only  legitimate  inference 
is,  that  the  conclusion  is  not  proved  by  those  premises ; 
for  it  may  be  conclusively  proved  by  other  unobjection- 
able premises. 

Where  the  conclusion  is  implied  in  the  premises,  the 
former  stands  as  high  as  the  latter,  but  no  higher.  If 
these  be  cognitions,  so  is  the  conclusion ;  and  the  same 
relation  holds  between  them  when  the  premises  are  only 
probabilities :  that  of  the  conclusion  is  as  strong  as  the 
latter's,  but  not  stronger.  It  must  be  carefully  observed, 
however,  that  the  converse  does  not  hold  true.  False  or 
doubtful  premises  do  not  prove  false  or  doubtful  conclu- 
sions, nor  exclude  other  proofs  that  they  are  true.  To 


288  SOPHISMS.  [CHA±>.  XVIII. 

warrant  us  in  assuming  that  a  conclusion  is  false,  we 
must  have  positive  proof  that  it  is  so ;  and  the  fact  that 
the  premises  may  be  false,  or  that  the  conclusion  may 
not  be  implied  in  them,  furnishes  no  such  proof. 

This  fallacy  is  one  into  which  we  are  very  readily  led 
by  prejudices.  We  are  apt  to  pay  too  little  attention  to 
our  premises,  when  they  establish  a  favorite  conclusion ; 
and  when  the  conclusion  is  strongly  repugnant  to  our 
desires,  we  are  inclined  to  reject  the  premises  which 
prove  it,  without  giving  them  a  careful  consideration. 

2.  Inferring  the  converse  occurs  where  we  infer  that  a 
proposition  is  true,  because  its  converse  is  true,  as  when 
we  infer  that  every  equiangular  triangle  is  equilateral, 
because  every  equilateral  triangle  is  equiangular.     This 
fallacy  often  produces  conviction,  not  only  on  account  of 
the  great  resemblance  which  a  proposition  bears  to  its 
converse,  but  from  the  fact  that  the  converse  is  often 
true,  although  the  case  is  generally  otherwise.    Although 
every  horse  is  a  quadruped,  yet  every  quadruped  is  not 
a  horse.     We  may,  indeed,  express  a  proposition  in  such 
a  way  as  to  render  its  converse  true,  by  making  its  sub- 
ject and  predicate  identical :   but  propositions  of  this 
class. are  only  an  exception  to  the  general  rule;  and  the 
cases  in  which  the  converse  is  true  accidentally  (as  in  the 
instance  mentioned  above)  are  too  few  to  be  taken  into 
account. 

A  common  example  of  this  sophism  is,  where  we  infer 
that  one  thing  is  identical  with  another,  because  both  be- 
long to  the  same  general  class.  White  is  a  color,  and 
black  is  a  color :  therefore  black  is  white.  So,  every  wise 
man  carefully  considers  the  future,  and  John  does  so : 
therefore  he  is  wise.  It  is  assumed,  in  all  such  cases, 
that  the  converse  is  true ;  and  hence  the  fallacy.  Al- 
though white  is  a  color,  every  color  is  not  white. 

3.  Altering  propositions  is  where  we  erroneously  as- 
sume, in  the  course  of  an  argument,  that  something  has 
been  already  proved,  or  has  appeared  to  be  true,  which 
is  employed  accordingly,  as  a  sound  premise,  while  it 
differs  materially  from  that  whose  place  it  thus  usurps. 
The  previous  proposition  generally  bears  some  resem- 
blance to  the  other:   but  it  is  less  extensive,  or  it  has 
been  proved  only  with  certain  qualifications  or  restric- 
tions, which  are  afterwards  overlooked,  or  it  is  proved 
true  only  in  another  sense  from  that  assumed,  or  it  lacks 
something  important  which  is  afterwards  added. 


SEC.  2.]  ALTERING  PROPOSITIONS.  289 

This  fallacy  is  greatly  fostered  by  the  defects  of  lan- 
guage ;  and  it  is  often  disguised  by  being  combined  with 
ambiguous  expression.  Here  the  ambiguous  terms  are 
used  in  different  senses,  throughout  the  argument,  while 
some  of  these  are  not  true,  in  the  sense  in  which  they 
would  require  to  be  so,  to  render  the  reasoning  valid. 
When  it  is  said  that  "  three  and  two  are  five,  and  five  is 
one  number:  therefore  three  and  two  are  one  number" 
—the  word  are,  in  the  first  proposition,  should  have  the 
sense  of"  are  identical  with,"  in  order  to  sustain  the  con- 
clusion, as  understood ;  and,  in  this  sense,  the  proposition 
is  false.  Three  and  two  are  no  more  five  than  so  many 
copper  coins  are  one  silver  coin.  They  are  only  equiva- 
lent to  five ;  and,  in  this  sense,  the  conclusion  is  proved  : 
three  and  two  are  equivalent  to  one  number.  So  it  can 
be  proved  that  "some  men  are  wise,"  and  "some  men 
are  fools :"  but  it  does  not  thence  follow  that  fools  are 
wise,  since  the  expression  "  some  men"  denotes  totally 
distinct  objects,  in  the  two  propositions. 

An  amusing  instance  of  this  combination  is  found  in 
the  old  story  of  Protagoras  the  Sophist,  and  his  pupil 
Euathlus.  The  former  taught  the  latter  Rhetoric,  on 
condition  that  he  should  be  paid  for  his  services,  if  his 
pupil  were  successful  in  pleading  his  first  case.  Euathlus 
having  failed  to  commence  practice,  Protagoras  sued 
him  ;  and  he  pleaded  his  own  case.  So  this  was  his  first 
case.  Therefore  Protagoras  was  bound  to  win :  for,  if 
the  decision  were  in  his  favor,  Euathlus  was  bound  to 
pay,  in  virtue  of  the  judgement ;  and  if  it  was  otherwise, 
Euathlus  gained  his  case,  and,  therefore,  Avas  bound  to 
pay,  in  virtue  of  the  contract.  But,  on  the  other  hand, 
Euathlus  was  bound  to  win :  for,  if  the  decision  was,  that 
he  should  pay,  he  had  lost  his  first  case,  and,  therefore, 
should  pay  nothing,  by  the  terms  of  the  contract :  but  if 
the  decision  was  otherwise,  this  left  him  free. 

§  2.  SOPHISMS  or  GENERALIZATION. — Nature  of  these  Fallacies. — 
(1)  Sophistical  Extension. — Frequent  source  of  it. — With  what  oft- 
en combined. — Influence  of  the  Combination. — (2)  Sophistical  In- 
clusion.— (3)  Sophistical  Contraction. — (4)  Sophistical  Exclusion. 
— (5)  Sophistical  Combination. — Why  often  undetected. — (6)  Im- 
aginary Universality. — Why  prevalent.— Caution. 

This  class  consists  in  generalizing  further  than  our  ac- 
tual knowledge  warrants,  or  the  converse :  and  there  are 
six  principal  kinds  of  it. 

" 


290  SOPHISMS.  [CHAP.  XVIII. 

1.  Sophistical  extension  is  where  we  assume  that  things 
found  together  in  certain  cases,  are  always  connected,  or 
that  a  certain  property  is  common  to  every  one  of  a 
class,  since  it  belongs  to  several  of  its  individuals  or 
tribes.     In  other  words,  we  mistake  an  empirical  for  a 
scientific  generalization.     Some  men  have  been  deceived 
by  several  of  their  neighbours ;  so  they  infer  that  all 
mankind  are  dishonest :  many  have  been  found,  tinder 
certain  circumstances,  to  lie ;  therefore  it  is  inferred  that 
nobody  can  be  safely  believed,  under  any  circumstances. 
Others  find  that  certain  things  related  by  historians  are 
untrue :  so  they  conclude  that  all  history  is  unworthy  of 
credit.     Many  things  are  uncertain,  and  many  falsehoods 
have  been  believed  as  truths :  therefore  they  infer  that 
nothing  is  certain. 

Many  fallacies  of  this  kind  originate  in  the  fact  that  a 
certain  property  has,  not  unfrequently,  been  found  to 
extend  beyond  the  cases  first  observed  ;  and  hence  it  is 
erroneously  inferred  that  it  extends  indefinitely.  A  negro 
of  Central  Africa  is  apt  to  infer  that  all  men  are  black 
or  brown,  while  some  natives  of  Northern  Europe  once 
inferred  that  all  mankind  are  white.  The  experience  of 
so  many  cases  leads  to  a  tacit  inference  that  they  are  the 
effects  of  some  constant  and  unvarying  cause,  which,  how- 
ever, may  have  no  existence. 

This  fallacy  is  frequently  combined  with  those  of  com- 
prehension. Not  only  is  there  no  real  induction,  but  the 
facts  on  which  we  reason  are  either  inaccurately  or  par- 
tially observed ;  and  a  more  extended  or  careful  view 
would  speedily  explode  the  generalization.  Judicial 
Astrology  is  a  notable  instance  of  this  combination.  It 
assumed  that  the  position  of  the  planets,  at  the  time  of 
a  person's  birth,  determined  his  character  and  future 
destiny,  although  many  men,  born  at  the  same  time, 
have,  in  every  age,  exhibited  the  most  different  charac- 
ters and  fortunes,  on  which  the  aspect  of  the  planets  had 
not,  in  reality,  the  least  influence. 

2.  In  sophistical  inclusion  we  assume,  without  satis- 
factory proof,  that  several  things  which  agree  in  some 
respects,  agree  in  others  also,  and  thus  infer  that  all  be- 
long to  a  particular  class,  when,  in  fact,  they  may  not. 
Thus,  naturalists  have  sometimes  ranked  a  species  with 
a  genus  to  which  it  did  not  belong,  on  their  own  princi- 
ples.    So  men  often  attribute  to  others  characters  which 


SEC.  2.]          FALLACIOUS  GENERALIZATION.  291 

they  do  not  possess,  because  they  exhibit  certain  appear- 
ances which  accompanied  the  supposed  character  in  other 
cases,  but  do  not,  in  the  case  in  question.  In  the  same 
way,  the  opinions  of  certain  persons  have  been  classed 
with  a  school  to  which  they  do  not  belong,  because  they 
have  several  things  in  common;  and  all  diseases  have 
sometimes  been  classed  under  a  few  general  heads,  so 
that  affections  essentially  different,  and  requiring  differ- 
ent treatment,  were  classed  together.  Other  common 
instances  of  this  sophism  are,  that  things  essentially  dif- 
ferent are  quite  alike,  because  they  happen  to  be  called 
by  the  same  name,  and  that  language  faithfully  expresses 
the  realities  of  nature,  in  every  instance,  when,  in  fact,  it 
fails  to  do  so,  in  many  important  cases. 

3.  Sophistical  contraction  occurs  where  an  induction 
is  mistaken  for  an  empiricism,  and  it  is  assumed  that  the 
facts  beyond  those  immediately  observed  are  different, 
when,  in  reality,  they  are  as  uniform  as  the  course  of  na- 
ture.    This  fallacy  is  the  converse  of  sophistical  exten- 
sion :  and  we  have  an  instance  of  it  in  the  common  remark 
that  a  certain  kind  of  diet  is  very  conducive  to  the  health 
of  the  speaker,  although  he  admits  that  it  has  been  found 
injurious  in  other  cases;  and, in  fact,  there  is  conclusive 
proof  that  it  must  always  be  so.     Another  common  in- 
stance is,  where  a  man  infers  that  he  can,  by  some  means 
or  other,  escape  the  certain  and  inevitable  consequences 
of  a  dissipated  life,  while  he  is  well  aware  that  they  have 
followed  in  other  cases. 

4.  In  sophistical  exclusion  we  assume,  without  satis- 
factory proof,  that  things  which  differ  in  some  respects, 
differ  in  others  also,  and  consequently  infer  that  they  be- 
long to  different  classes,  when  possibly  they  do  not.     It 
is  the  converse  of  sophistical  inclusion,  and  leads  us  to 
exclude  an  individual  or  a  species  from  its  proper  class. 
Thus  it  is  often  assumed  that  a  man  does  not  possess  a 
certain  character,  because  he  does  not  exhibit  peculiari- 
ties which  accompanied  such  a  character  in  other  cases, 
but  in  fact  do  not,  in  his  case.     Another  instance  is, 
where  it  is  inferred  that  things  are  materially  different 
because  they  are  called  by  different  names,  while  they 
may  all  be  modifications  of  the  same  thing,  and  essen- 
tially alike.    Naturalists  fall  into  this  sophism  when  they 
form  a  mere  variety  into  a  distinct  species,  or  exclude  a 
species  from  its  proper  genus,  because  it  does  not  ex- 


292  SOPHISMS.  [CHAP.  XVIII. 

hibit  peculiarities  which  are  erroneously  believed  to  char- 
acterize the  class  from  which  it  is  excluded. 

5.  In  passing  from  several  special  propositions  to  a 
general  one,  which  professedly  embraces  them  all,  and  no 
more,  something  material  is  added  or  excluded,  forming 
the  fallacy  of  sophistical  combination.     It  frequently  es- 
capes detection,  especially  in  elaborate  arguments,  be- 
cause several  of  the  particular  propositions  are  unexcep- 
tionable, and  the  attention  is  diverted  from  the  objection- 
able part,  which  may  form  only  a  small,  though  possibly 
an  essential,  portion  of  the  general  proposition.     Foren- 
sic arguments  frequently  exemplify  this  fallacy,  by  draw- 
ing, from  the  testimonies  given,  some  general  conclusion, 
which  involves  a  material  assumption  of  which  no  satis- 
factory proof  has  been  given. 

6.  Imaginary  universality  is  where  we  assume  that  a 
proposition  is  true  or  false  universally,  because  it  lias 
been  proved  to  be  so  generally.     This  sophism  is  of  fre- 
quent occurrence,  because  there  is  a  general  prejudice  in 
favor  of  excluding  all  exceptions  to  general  laws  or  rules, 
while  these  may  exist  notwithstanding.     Most  men  are 
rational  and  two-handed,  but  some  are  not.     We  can 
never  safely  admit  the  universality  of  a  proposition  ex- 
cept where  this  has  been  rigidly  proved ;  and  this  can 
never  be  done,  beyond  the  bounds  of  necessary  truth. 

§  3.  SOPHISMS  OF  CAUSATIOX. — (1)  False  Cause. — Important  Distinc- 
tion.— (2)  False  Effect. — Error  regarding  Experience. — (3)  Con- 
founding Cause  and  Effect. — (4)  Hypothetical  Causes. — (5)  Mis- 
taking the  chief  Cause. — (6)  Mistaking  the  chief  Effect.— (7)  Mis- 
taking the  ultimate  Cause. — (8)  Sophistical  Explanation. — (9)  So- 
phistical Induction. — (10)  Sophistical  Proof. — Relation  of  Proof  to 
Cause. — (11)  Sophistical  Relation. — Why  prevalent.— (12)  Ex- 
cluding Causes. — (13)  Excluding  Effects. — Why  prevalent. — (14) 
Imaginary  Effect. — Caution. — (15)  Imaginary  Cause. — Frequent 
Combinations. — By  what  this  class  of  Sophisms  is  particularly  af- 
fected. 

This  class  comprises  those  sophisms  in  which  we  err 
regarding  causes  and  effects.  The  following  enumera- 
tion includes  the  most  common. 

1.  False  cause  occurs  where  a  mere  antecedent  or  con- 
comitant is  inferred  to  be  a  cause,  while  the  effect  may 
depend  wholly  on  other  agencies.  A  uniform  antecedent 
or  concomitant  is  a  sign  of  the  consequent:  but,  before 
we  are  justified  in  considering  it  a  cause,  we  must  know 
that  it  is  concerned  in  producing  the  effect. 


SEC.  3.]  SOPHISMS  OP  CAUSATION.  293 

Many  superstitions  are  examples  of  this  fallacy.  A 
pagan  fails  to  present  the  usual  oiferings  to  the  gods :  he 
is  taken  sick,  and  at  once  attributes  this  to  the  supposed 
anger  of  the  offended  deities.  Another  has  used  some 
silly  charm,  before  engaging  in  an  important  undertak- 
ing :  he  succeeds,  and  attributes  it  to  the  influence  of  the 
charm.  Medicine  and  politics,  also,  furnish  numerous  in- 
stances of  this  fallacy.  A  person  takes  a  medicine,  and 
recovers  from  his  disease :  the  cure  is  attributed  to  the 
remedy,  although  possibly  it  may  have  only  retarded  his 
recovery,  which  was  effected  by  the  healing  powers  of 
the  system,  in  spite  of  the  pernicious  effect  of  the  medi- 
cine. So  politicians  have  sometimes  attributed  public 
prosperity  or  adversity  to  certain  laws,  which,  in  fact, 
operated  wholly  the  other  way. 

2.  False  effect  is,  where  a  consequent  or  concomitant  is 
inferred  tp  be  the  effect  of  an  agency  of  which  it  may 
possibly  be  quite  independent.     A  man's  success,  in  one 
case,  and  his  failure,  in  another,  have  been  frequently 
deemed  the  effects  of  agencies  by  which  they  were  not, 
in  the  least,  influenced.    The  Moon  is  incessantly  chang- 
ing, and  so  is  the  weather:  hence  changes  of  the  former 
are  speedily  followed  by  changes  of  the  latter,  as  a  mat- 
ter of  course ;  and  yet  these  have  often  been  believed  to 
be  effects  of  the  former,  although  further  observation 
would  show  that  the  two  classes  of  phenomena  have  not 
the  least  connection  with  each  other. 

Where  a  certain  change  follows  the  supposed  cause,  it 
is  sometimes  confidently  declared  that  experience  proves 
the  point,  when  all  it  proves  is,  that  one  followed  the  oth- 
er, and  it  may  have  been  its  effect  no  more  than  night  is 
the  effect  of  day,  or  winter  the  effect  of  summer.  The 
premonitory  symptoms  of  a  disease  are  its  uniform  ante- 
cedents :  but,  instead  of  being  its  cause,  they  are  only 
early  effects  of  the  common  cause. 

3.  We  mistake  the  order  of  cause  and  effect,  making 
that  the  cause  which  is,  in  reality,  the  effect,  and  con- 
versely, forming  the  sophism  of  confounding  cause  and 
effect.     We  are  very  liable  to  fall  into  this  error  where 
the  cause  and  effect  appear  simultaneously,  or  where  the 
effect  reacts  and  strengthens  the  cause,  or  where  two 
things  mutually  produce  each  other,  so  that  what  is,  in 
one  case,  the  effect,  is,  in  another,  the  cause.     Thus  loose 
thinking  produces  loose  acting,  while  the  latter  increases 


294  SOPHISMS.  [CHAI>.  XVIII. 

and  confirms  the  former,  or  even  produces  it  independ- 
ently. A  pernicious  instance  of  this  fallacy  is,  the  opin- 
ion that  severe  training  renders  children  hardy,  because 
many  who  bore  it  are  so.  They  are  not  hardy,  because 
they  were  treated  severely ;  but  they  bore  such  treat- 
ment unflinchingly,  because  they  were  originally  very 
hardy ;  and  they  would  be  hardier  than  they  are,  if  they 
had  been  more  rationally  treated.  The  sophism  has 
caused  the  deaths  of  many  thousands  of  children,  and 
loss  of  health  and  strength  to  still  greater  numbers. 

4.  Hypothetical  causes  occurs  where  supposed  agencies 
are  inferred  to  be  the  causes  of  the  effect  in  question, 
when  possibly  they  have  no  existence.     This  fallacy  is 
frequently  exemplified  in  the  motives  assigned  for  the 
actions  of  others,  where  these  are  not,  in  reality,  known. 
A  man  of  good  principles  is  apt  to  assign  motives  to 
which  the  party  in  question  may  be  an  entire  stranger, 
while  persons  of  a  different  character  are  inclined  to  at- 
tribute everything  to  bad  and  sordid  motives,,  such  as 
usually  sway  themselves.     This  fallacy  abounds  in  Scho- 
lastic Physics.     Water  rose  in  a  pump,  because  nature 
abhorred  a  vacuum :  descending  bodies  moved  faster  and 
faster,  because  their  motion  was  violent,  and  not  natural : 
air  occupied  the  upper  regions,  because  that  was  its  prop- 
er place :  muscular  contraction  was  effected  by  the  ani- 
mal spirits — and  so  forth. 

5.  Mistaking  the  chief  cause  occurs  where  one  of  sev- 
eral agencies  is  inferred  to  be  the  sole  or  chief,  when  it 
is  possibly  only  a  minor  cause,  having  comparatively  lit- 
tle influence  on  the  effect.     A  man  whose  constitution 
has  been  ruined  by  dissipation,  takes  a  slight  cold,  and 
dies.     His  death  is  attributed  to  the  cold,  although  it 
would  have  produced  no  serious  effect  on  him,  if  his  con- 
stitution had  retained  its  original  vigor.     Another  com- 
plains of  bad  health,  which  he  attributes  chiefly  to  hard 
study,  labor,  or  exposure,  when,  in  fact,  it  has  proceeded 
mainly  from  luxurious  living. 

6.  Mistaking  the  chief  effect  is,  inferring  that  a  minor 
or  secondary  is  the  chief  effect.     A  broken  down  de- 
bauchee will  sometimes    complain  of  a  comparatively 
trifling  evil  result  of  his  vicious  courses,  and  overlook 
the.  fact  that  he  is  a  total  wreck :  so  a  politician  some- 
times inveighs  against  a  law  as  very  bad,  because  it  pro- 
duces some  evil,  while  he  overlooks  the  fact  that  it  pro- 
duces a  much  greater  amount  of  good. 


SEC.  3.]  SOPHISMS  OF  CAUSATION.  295 

7.  Mistaking  the  ultimate  cause  is,  where  we  infer  that 
some  intermediate  is  the  ultimate  cause,  and  requires  no 
further  explanation,  when,  in  fact,  the  last  at  which  we 
have  arrived  must  be  attributed  to  some  remoter  cause. 
Instances  of  this  fallacy  abound  in  various  treatises  on 
Physics.     When  a  phenomenon  has  been  traced  to  elec- 
tricity, for  example,  it  is  inferred  that  the  ultimate  cause 
has  been  disclosed,  whereas  the  motions  of  electricity  re- 
sult from  one  or  more  agents  beyond  itself,  as  certainly 
as  it  is  the  immediate  cause  of  the  phenomenon  in  ques- 
tion ;  and,  until  that  has  been  unfolded,  we  continue  ig- 
norant of  the  ultimate  cause. 

8.  Sophistical  explanation  occurs  where  it  is  inferred 
that  the  cause  has  been  clearly  proved  when  only  some 
explanation  is  given,  which  possibly  refers  the  phenome- 
non to  some  acknowledged  law,  but  which  assigns  no 
real  cause.     "  India  rubber  contracts,  when  it  has  been 
stretched,  because  it  is  elastic:  the  particles  of  solids 
stick  together,  because  they  are  adhesive :  and  streams 
flow  downward,  because  all  bodies  gravitate  towards  the 
center."     Such  expressions  only  refer  a  particular  phe- 
nomenon to  a  general  law,  and  unfold  the  cause  of  noth- 
ing.    They  only  state  that  the  phenomenon  is  owing  to 
what  produces   something  else,  on  which  no  light  is 
thrown. 

9.  Sophistical  induction  is,  where  inductive  truths  are 
mistaken  for  efficient  causes.     This  sophism  differs  from 
the  preceding  in  attributing  causal  power  to  a  mere  law, 
whereas  the  other  refers  us  to  some  real,  though  unde- 
fined, cause,  which  produces  the  general  phenomenon. 
Instances  of  it  are  found  in  statements  which  attribute 
to  the  laws  of  electricity,  magnetism,  and  gravitation,  the 
numerous  changes  exhibited  by  their  several  phenomena, 
and  which  result  from  some  force  that  is  unexplained,  or 
even  unsuspected.     A  law  is  merely  a  command,  or  a 
general  truth,  and  cannot  be  an  efficient  cause  of  any- 
thing.   Laws  and  agents  are  totally  different  things  ;  and 
this  fallacy  consists  in  confounding  them,  and  attributing 
to  the  former  what  cannot  possibly  belong  to  anything 
but  the  latter. 

10.  Sophistical  proof  occurs  where  we  mistake  the 
proof  for  the  cause,  and  attribute  to  the  former  what  be- 
longs to  the  latter.     When  we  have  proved  that  a  cer- 
tain agent  operates,  which  uniformly  produces  a  particu- 


29G  SOPHISMS.  [CiiAP.  XVIII. 

lar  effect,  we  have  implicitly  proved  the  existence  of  the 
latter.  But  the  converse  does  not  hold  true :  we  may 
prove  that  a  certain  effect  exists  without  proving  any- 
thing regarding  its  particular  cause.  The  appearance  of 
ice  on  the  waters  is  a  proof  that  there  has  been  cold 
weather :  but,  instead  of  being  the  cause,  it  is  an  effect. 
This  fallacy  is  fostered  by  the  habit  of  employing  the 
same  conjunctions  to  denote  causes  and  proofs. 

11.  Sophistical  relation  is,  inferring  that  effects  resem- 
ble their  causes,  or  that  effects  of  a  common  cause  are  all 
alike  in  kind,  and  proportional  to  its  intensity;  or,  con- 
versely, that  different  effects  must  proceed  from  agencies 
different  in  kind,  which  are  proportional  to  the  effects. 
This  sophism  is  very  prevalent,  because  the  inferences 
frequently  hold  true,  and  hence  the  exceptions  are  over- 
looked.    Yet  these  are  neither  few  nor  unimportant. 
Thus,  most  of  those  agencies  which  excite  pleasant  sen- 
sations, produce  pain  when  they  act  with  intensity,  such 
as  heat,  light,  and  various  sounds.     So  the  effects  of 
property  on  a  man's  well-being  are  by  no  means  propor- 
tional to  its  amount.     The  contrary  inference  is  a  veiy 
common  and  pernicious  instance  of  this  fallacy.     An  ap- 
peal to  experience  is  generally  necessary,  in  order  to  as- 
certain whether  the  relations  inferred  by  this  sophism 
really  exist,  and  also  to  ascertain  the  common  origin  of 
the  varying  effects  of  the  same  cause,  acting  with  differ- 
ent degrees  of  intensity. 

12.  Excluding  causes  is  where  we  attribute  a  phenom- 
enon solely  to  certain  agencies,  and  exclude  or  overlook 
others,  which  operate  in  its  production.     The  fact  that 
an  agency  does  not  by  itself  produce  a  given  effect,  by 
no  means  proves  that  it  is  not  instrumental  in  its  produc- 
tion.    Water   alone  will  not  decompose  organic  sub- 
stances ;  yet  it  is  an  active  agent  in  such  decomposition. 
So  the  Sun  has  a  very  perceptible  effect  on  the  tides,  and 
causes  the  difference  between  spring  and  neap  tides,  al- 
though the  Moon's  influence  is  much  more  conspicuous. 
A  common  instance  of  this  sophism  is,  denying  that  the 
art  of  reading  is  not  an  important  means  of  moral  and 
intellectual  discipline,  because  its  effects  may  be  nuga- 
tory, unless  aided  by  other  agencies.     So  it  is  sometimes 
inferred  that  certain  bad  habits  have  not  operated  in  pro- 
ducing disease  or  premature  death,  because  other  agen- 
cies have  operated,  and  some  persons  have  been  long- 
lived  who  were  addicted  to  those  habits. 


SEC.  3.]  SOPHISMS  OF  CAUSATION.  297 

13.  Excluding  effects  is,  where  we  exclude  or  overlook 
certain  effects  of  an  agency,  and  infer  that  some  others 
are  tli3  sole  effects.     This  frequently  happens  in  investi- 
gating the  results  of  laws  and  of  morbific  agencies.     An 
instance  of  it  occurs  in  the  common  opinion  that  the  im- 
mediate effects  of  alcohol  on  the  human  frame  are  its  sole 
effects,  and  that  it  is  not  instrumental  in  producing  chron- 
ic disease  or  permanent  insanity. 

14.  Imaginary  effect  attributes  to  a  certain  cause  an 
effect  which  does  not,  in  reality,  exist.     Sometimes  there 
are  phenomena  resembling  that  which  is  assumed  to  ex- 
ist ;  but  they  are  materially  different.    In  other  instances, 
the  assumption  is  partially  true,  yet  it  differs  essentially 
from,  the  reality.     A  non-existing  phenomenon  can  have 
no  cause ;    and    consequently  any  argument  ostensibly 
proving  its  cause,  must  be  sophistical.     Hence,  before 
inquiring  into  the  cause  of  a  supposed  or  assumed  phe- 
nomenon, we  should  ascertain  whether  it  is  a  fact.    Cases 
are  not  rare  in  which  much  time  has  been  spent  in  inves- 
tigating the  causes  of  imaginary  effects,  which  never  ex- 
isted.    An  instance  of  the  sophism  occurs  when  it  is  be- 
lieved that  a  man  recovered,  by  means  of  a  certain  treat- 
ment, from  a  disease  which  he  never  had.    So  a  politician 
sometimes  attributes  to  certain  laws  or  public  acts,  good 
or  evil  which  never  existed. 

15.  Imaginary  cause  occurs  where  an  effect  is  attrib- 
uted to  an  agency  which  never  existed,  and  which  evi- 
dently can  produce  no  effect.     Consequently  any  proof 
that  it  has  done  so  must  be  fallacious.     A  physician 
sometimes  attributes  the  cure  of  his  patient  to  a  medi- 
cine which  was  duly  prescribed,  but  which  the  latter 
never  took ;  and  a  politician  has  been  known  to  attrib- 
ute good  or  evil  to  acts  -of  the  ruling  powers  which  were 
never  performed.     This  and  the  preceding  fallacy  are  al- 
ways combined  with  some  paralogism,  which  they  dis- 
guise and  render  less  liable  to  detection. 

All  the  sophisms  of  causation  are  frequently  combined 
with  those  of  comprehension  and  signs.  Facts  are  either 
overlooked,  misapprehended  or  misinterpreted  ;  and  then 
Ave  reason  sophistically  upon  a  wrong  view  of  the  sub- 
ject. A  certain  phenomenon,  for  instance,  is  assumed  to 
be  a  uniform  antecedent,  when  careful  and  continued  ob- 
servation would  show  that  it  is  only  an  occasional  antece- 
dent ;  and  then  it  is  sophistically  inferred  to  be  the  cause. 

N  2 


298  SOPHISMS.  [CHAP.  XVIII. 

This  class  of  fallacies  is  particularly  affected  by  igno- 
rance and  prejudices,  since  the  truth  is  not  generally  ob- 
truded on  our  Comprehension,  but  must  be  learned  by 
a  close  and  cautious  view  of  the  subject. 

§  4.  SOPHISMS  or  PROBABILITY. — Nature  of  these  Fallacies. — (1)  In- 
ferring the  Probable. — (a)  Inferring  Hypotheses. — (b)  Accumula- 
ting Probabilities. — Important  Distinction. — (c)  Friends'  Opinions. 
—  (d)  One-sided  Arguments.  —  (e)  Harmonizing  Conclusions. — 
Why  frequent. — (f)  Contingent  Connective. — Frequent  Combina- 
tion.— (g)  Incomprehensible  Connective. — Important  Distinction. 
— (h)  Inconclusive  Investigation. — (i)  Sophistical  Leap. — Distinc- 
tion.— (2)  Rejecting  the  Improbable. — (a)  Discordant  Opinion. — 
Its  extensive  Influence. — (b)  Overlooking  the  Alternative. — Why 
prevalent. — Its  Operation. — (c)  Rejecting  Theories.  —  Frequent 
source  of  this  Sophism. — (d)  Severing  Probabilities. — (e)  Enemies' 
Opinions. — (f)  Mortifying  proofs. — Effects  of  this  Sophism. — (g) 
Imaginary  Absurdity. — Cause  of  its  great  Influence. — (h)  Sophist- 
ical Distinction. — Where  frequent. — Means  of  determining  wheth- 
er a  Distinction  is  material. — (3)  Varying  Probability. — (a)  Exag- 
gerating Probability. — Frequent  Combination. — (b)  Diminishing 
Probability. — (c)  Exaggerating  Improbability. — (d)  Diminishing 
Improbability. — Combinations. — Why  such  Fallacies  prevalent. — 
Two  Sources  of  them. — Why  Fallacies  of  Probability  are  very  prev- 
alent and  influential. — Frequent  Combinations. 

This  class  of  sophisms  consists  in  confounding  proba- 
bility with  certainty,  or  mistaking  the  character  of  the 
probability :  and  there  are  three  principal  kinds  of  it, 
each  of  which  comprises  several  sorts. 

1.  We  infer  that  a  proposition  is  true,  because  it  ap- 
pears probable,  while  it  may,  in  reality,  be  false.  This 
we  term  inferring  the  probable,  of  which  the  following 
sorts  are  common. 

(a.)  Inferring  hypotheses  is  where  we  infer  that  an 
hypothesis  or  supposition  is  true,  because  it  is  rendered 
probable  by  various  facts,  when.it  may  possibly  be  dis- 
provable  by  conclusive  arguments  or  evidence.  The  his- 
tory of  science  exhibits  many  instances  of  this  fallacy, 
from  the  crystaline  spheres,  epicycles  and  eccentrics  of 
the  ancient  astronomers,  to  the  habitable  Moon  and  plan- 
ets of  later  ages.  An  hypothesis  often  appears  so  beau- 
tiful, harmonious,  complete,  and  systematic,  that  its  au- 
thor or  his  disciples  are  ready  to  adopt  it  as  established, 
without  requiring  proof  that  it  is  true,  although  it  may 
possibly  be  easy  to  discover  facts  by  which  it  is  com- 
pletely exploded. 

A  frequent  instance  of  this  modification  is,  inferring 


SEC.  4.]  SOPHISMS  OF  PHOBABILITY.  299 

that  a  certain  operative  agency,  which  uniformly  pro- 
duces the  effect  in  question  when  it  is  not  counteracted, 
must  have  actually  produced  it,  while  possibly  the  ordi- 
nary result  was  prevented  by  some  counteracting  agen- 
cy. Or,  conversely,  it  is  inferred  that  a  known  effect 
must  have  proceeded  from  a  particular  agency,  when  it 
may  possibly  have  resulted  from  any  of  several  others. 
By  this  means  persons  have  been  charged  with  crimes 
that  were  never  committed,  and  the  misdeeds  of  one 
have  been  attributed  to  another,  against  whom  there 
were  suspicious  circumstances. 

(b.)  Accumulating  probabilities  occurs  where  it  is  in- 
ferred that  a  proposition  is  true,  because  it  is  supported 
by  several  dependent  probabilities,  or  probabilities  of 
probabilities.  These  are  confounded  with  concurrent 
and  independent  probabilities,  where  every  one  strength- 
ens the  preceding,  instead  of  weakening  it,  as  happens 
with  the  former  class.  The  implicit  credit  frequently 
given  to  the  statements  of  persons  who  derived  their  in- 
formation from  each  other,  is  a  common  instance  of  this 
fallacy.  It  is  not  perceived  that,  in  such  cases,  the  more 
witnesses,  the  less  credibility. 

(c.)  Friends'  opinions  is,  where  we  infer  that  a  propo- 
sition is  true,  because  our  friends,  or  persons  whom  we 
deem  competent  witnesses  and  good  judges,  state  or  be- 
lieve it,  Avhen  there  is  no  conclusive  proof.  Many  men 
hardly  ever  investigate  a  subject  of  any  difficulty  inde- 
pendently:  they  inquire  what  such  and  such  men  say  or 
think  of  it,  without  ever  seeking  or  finding  any  conclu- 
sive proof;  and  then  they  adopt  those  men's  opinions  as 
known  truths.  A  common  case  of  this  form  is,  where 
we  receive  as  conclusive  the  testimony  of  a  witness  of 
whom  we  think  favorably,  while  it  establishes  only  a 
probability. 

(d.)  The  sophism  of  one-sided  arguments  is,  where  ar- 
guments have  been  adduced  which  render  the  proposi- 
tion in  question  probable,  and,  therefore,  it  is  inferred  to 
be  true,  while  other  arguments,  w^hich  militate  against 
it,  are  overlooked.  One  of  the  most  common  cases  is, 
the  erroneous  opinions  which  many  hold  regarding  their 
own  characters,  desires,  pursuits  or  expectations.  The 
arguments  which  favor  the  bright  side  are  seized  with 
avidity,  and  adopted  as  conclusive,  while  those  of  a  con- 
trary tendency  are  overlooked,  although  they  may  possi- 


300  SOPHISMS.  [CHAP.  XVIII. 

bly  be  more  cogent  than  the  others.  Hence  the  errone- 
ous views  which  men  have  so  frequently  held  regarding 
the  character  of  themselves,  their  nation,  age,  religious 
denomination  or  political  party ;  and  hence  pride  and 
self-sufficiency,  coupled  with  contempt  for  others,  and  a 
fixed  determination  to  persist  in  present  belief  and 
courses,  right  or  wrong. 

(e.)  Harmonizing  conclusions  is,  where  we  infer  that 
a  proposition  is  true,  because  it  appears  to  harmonize 
with  some  real  or  supposed  truth,  or  it  agrees  with  our 
own  opinions,  or  its  reception  as  true  removes  a  diffi- 
culty. This  form  has  been  a  fertile  source  of  error,  be- 
cause one  truth  always  harmonizes  with  another,  and  we 
are  strongly  inclined  to  adopt  as  true  what  tallies  with 
our  own  views  and  opinions.  Instances  of  it  occur  in 
the  numerous  cases  in  which  the  false  statements  of  his- 
torians, travelers  or  newsmen  have  been  received  as  true, 
because  they  accorded  with  the  opinions  of  those  to 
whom  they  were  addressed.  Another  common  instance 
is,  where  we  receive  a  charge  against  a  person  as  true  or 
false,  according  to  our  opinion  regarding  his  previous 
character,  while  the  evidence  may  prove  the  reverse. 

(f.)  Contingent  connective  is,  where  a  contingent  truth 
is  employed  as  the  connective  of  a  syllogism,  instead  of 
an  intuition.  A  common  instance  of  this  form  is,  where 
an  induction  is  employed  as  a  connective,  as  when  it  is 
argued  that  a  certain  person  must  die,  since  all  men  are 
mortal,  or  that  an  animal  must  have  such  an  organiza- 
tion, since  every  one  of  the  species  has  it.  The  fallacy 
is  often  combined  with  that  of  false  extension,  the  as- 
sumed induction  being  only  an  empiricism,  as  when  it  is 
inferred  that  a  certain  man  must  be  of  such  a  character, 
since  every  one  of  his  nation  bears  it,  when,  in  fact,  it  is 
only  a  prevalent  character  among  them,  and  by  no  means 
universal. 

(g.)  Incomprehensible  connective  occurs  where  a  prop- 
osition is  employed  as  a  connective,  because  its  contra- 
dictory is  incomprehensible,  whence  it  is  erroneously  as- 
sumed to  be  self-evident,  when  it  may  possibly  be  false. 
Instances  of  it  occur  in  some  mathematical  demonstra- 
tions and  philosophical  speculations.  Thus,  it  has  some- 
times been  assumed  as  self-evident  that  a  vanishing  quan- 
tity must  have  some  finite  value,  and  that  duration  can- 
not be  eternal,  nor  extension  infinite.  A  notable  instance 


SEC.  4.]  SOPHISMS  OF  PROBABILITY.  301 

is,  the  ancient  puzzle  which  professed  to  prove  that  the 
swift-footed  Achilles  could  never  overtake  a  turtle,  be- 
cause the  latter  always  advanced  a  little,  while  the  man 
was  traversing  the  intervening  space.  This  was  assumed 
to  be  subdivided  indefinitely ;  and,  as  we  cannot  com- 
prehend an  infinite  number,  we  are  apt  to  infer  that  it 
would  take  an  endless  time  to  traverse  an  infinite  num- 
ber of  small  spaces,  whereas  the  time  of  traversing  the 
intervals  would  become  shorter,  exactly  as  they  became 
smaller,  and  one  minute  can  be  divided  and  subdivided 
without  limit,  as  well  as  one  mile. 

There  are  many  truths  that  transcend  our  comprehen- 
sion :  and,  consequently,  we  can  never  safely  assume  that 
a  proposition  is  necessarily  true,  because  we  cannot  com- 
prehend its  contradictory.  This  raises  only  a  probabil- 
ity that  it  is  true ;  but,  instead  of  being  necessarily  so, 
there  is  sometimes  conclusive  proof  that  it  is  false.  The 
incomprehensible  and  the  self-evidently  impossible,  al- 
though often  confounded,  are  widely  different  things. 

(A.)  Inconclusive  investigation  is,  where  we  have  in- 
vestigated the  character  of  a  proposition,  and  we  infer 
that  it  is  certainly  true,  while  our  labors  establish  no 
more  than  a  probability,  because  the  criterion  of  truth 
has  not  been  properly  applied,  on  one  or  more  points. 
Instances  of  this  form  abound  in  historical,  scientific,  and 
judicial  investigations,  as  well  as  in  common  life. 

(i.)  The  sophistical  leap  occurs  where  the  proposition 
has  appeared  to  be  very  probable,  and,  therefore,  it  is  in- 
ferred to  be  certain,  the  wide  gulf  that  separates  proba- 
bilities from  certainties  being  overleaped.  Future  evi- 
dence or  discoveries  may  disprove  the  strongest  proba- 
bility, and  show  that  it  is  wrholly  false,  or  at  least  annul- 
led by  an  equally  strong  counter  probability,  whereas 
they  cannot,  in  the  least,  invalidate  a  certainty,  although 
they  may  corroborate  it.  When  once  established,  a  cer- 
tainty continues  unchangeable  ever  afterwards,  while 
probabilities  are  subject  to  change  from  year  to  year,  or 
even  from  hour  to  hour. 

2.  Rejecting  the  improbable  is,  where  we  infer  that  a 
proposition  is  false,  because  it  appears  to  be  improbable, 
when  it  may  possibly  have  been  proved  conclusively. 
The  following  are  the  most  common  sorts. 

(a.)  Discordant  opinion  is,  where  we  infer  that  a  prop- 
osition is  false  or  unproved,  because  it  conflicts  with  our 


302  SOPHISMS.  [CHAP.  XVIII. 

own  opinions  or  experience.  Thus  one  error  often  leads 
to  several  others,  and  the  rejection  of  many  truths.  The 
fact  that  there  are  antipodes  was  long  rejected  by  the 
great  mass  of  mankind  as  an  absurdity ;  and,  until  re- 
cently, accounts  of  showers  of  stones  having  fallen  from 
the  sky,  were  generally  classed  with  the  old  story  of 
Vulcan  having  fallen  from  heaven  upon  Lemnos.  This 
fallacy  has  been  very  prevalent,  owing  to  the  general 
tendency  of  men  to  make  their  individual  views  and  ex- 
perience the  standard  of  truth,  and  to  reject  whatever  is 
incompatible  with  them,  although  the  former  may  be  er- 
roneous, and  the  latter  very  narrow. 

(b.)  Overlooking  the  alternative  is,  where  we  infer  that 
a  proposition  must  be  false,  because  there  are  proofs  that 
it  is  highly  improbable,  while,  in  reality,  its  rejection  in- 
volves a  much  greater  improbability,  or  even  an  impossi- 
bility. This  form  is  of  frequent  occurrence,  because  a 
very  high  degree  of  improbability  is  readily  confounded 
with  an  impossibility.  The  infinity  of  extension  and  the 
eternity  of  duration,  appear  highly  improbable,  as  they 
are  undoubtedly  incomprehensible :  yet,  if  we  deny  those 
attributes,  we  must  admit  that  the  former  has  bounda- 
ries, and  that  the  latter  had  a  beginning,  two  things 
which  are  absolutely  impossible. 

Owing  to  this  fallacy,  men  often  adhere  to  an  opinion 
which  involves  much  greater  difficulties  than  that  which 
they  reject  for  its  improbability.  They  dwell  upon  the 
difficulties  of  the  latter,  and  overlook  the  fact  that  these 
are  not  conclusive,  and  that  greater  difficulties  are  in- 
volved in  the  alternative,  which  they  must  receive,  if  the 
other  is  rejected.  Thus,  many  historical  statements  have 
been  rejected  as  improbable,  where  the  falsity  of  the  tes- 
timony would  be  a  much  greater  improbability,  or  even 
an  absurdity. 

(c.)  Rejecting  theories  is,  where  an  hypothesis  which 
has  been  proved  to  be  true,  is  rejected,  because  it  ap- 
pears improbable.  This  is  frequently  owing  to  its  clash- 
ing with  some  favorite,  but  groundless,  hypothesis  of  the 
rejecter :  but  it  often  proceeds  from  his  being  too  igno- 
rant, indolent,  or  narrow-minded  to  appreciate  the  proofs 
by  which  the  hypothesis  is  established. 

(d.)  /Severing  probabilities  consists  in  rejecting  conclu- 
sive circumstantial  evidence,  because  the  separate  cir- 
cumstances establish  only  a  probability,  which  is  believed 


SEC.  4.]  SOPHISMS  OF  PROBABILITY.  303 

to  be  rebutted  by  a  greater  antecedent  probability  against 
the  conclusion,  while  the  combined  force  of  all  the  evi- 
dences is  overlooked.  The  fallacy  is  like  maintaining 
that  twenty  men  cannot  raise  a  weight,  because  none  of 
them  separately  can  do  it.  A  common  instance  is,  where 
a  man  charged  with  a  crime,  is  believed  to  be  innocent, 
on  account  of  his  previous  good  character,  and  the  evi- 
dence against  him  being  wholly  circumstantial,  although, 
taken  altogether,  it  may  be  quite  irrefragable.  In  the 
same  way,  another  is  believed  to  be  guilty,  because  of 
his  bad  reputation,  and  none  of  the  exculpatory  circum- 
stances being  conclusive  ;  although  all  of  them  taken  to- 
gether may  be  quite  so. 

(e.)  Enemies'  opinions  consists  in  inferring  that  a  prop- 
osition is  false,  because  it  is  rejected  by  those  of  whom 
we  think  highly  and  adopted  or  testified  by  others  to 
whom  we  are  opposed  or  unfriendly,  while  the  proof  by 
which  it  is  sustained  has  never  been  properly,  if  at  all, 
examined,  and,  for  anything  that  appears  to  the  contrary, 
it  may  be  quite  conclusive.  This  sophism  is  the  con- 
verse of  friends'  opinions,  and  operates  similarly.  A 
common  instance  is,  where  we  reject  as  unsatisfactory 
the  conclusive  testimony  of  a  witness  whom  we  dislike, 
for  which  reason  we  think  it  highly  improbable,  and 
therefore  not  credible. 

(/*.)  Mortifying  proofs  is,  where  an  established  prop- 
osition is  rejected,  because  it  is  highly  distasteful  to  our 
wishes  or  feelings,  whence  we  infer  that  it  must  be  false. 
Prejudice  makes  it  appear  very  improbable,  and,  there- 
fore, it  is  inferred  that  there  must  be  some  radical  defect 
in  the  argument  or  testimony  by  which  it  is  sustained. 
Thus,  when  it  has  been  proved  that  a  man's  conduct,  on 
a  particular  occasion,  has  been  highly  culpable,  he  imme- 
diately appeals  to  the  supposed  purity  or  excellence  of 
his  motives,  as  invalidating  the  argument,  which  is  not 
in  the  least  affected  by  their  character.  So  men  are  apt 
to  believe  that  arguments  or  testimonies  which  militate 
against  the  excellence  of  their  own  character,  conduct, 
or  position  must  be  fallacious,  although  they  may  be 
quite  the  reverse. 

This  sophism  fosters  selfishness  and  bad  passions,  and 
throws  strong  obstacles  in  the  way  of  reforming  evil 
practices,  or  correcting  erroneous  opinions.  It  is  the 
counterpart  of  the  fallacy  of  one-sided  arguments,  which 
it  generally  accompanies  and  strengthens. 


304  SOPHISMS.  [CHAP.  XVIII. 

(g.)  Imaginary  absurdity  is,  where  a  proposition  is 
inferred  to  be  false,  because  it  is  erroneously  believed  to 
contradict  self-evident  or  palpable  truth.  Conclusive 
proof  has  often  been  thus  rejected.  It  is  so  pleasant  and 
easy  to  adopt  current  opinions  as  true,  so  difficult,  in 
many  cases,  to  find  truth,  and  so  unpleasant  to  discover 
we  have  believed  error,  that  a  great  portion  of  mankind 
have  been  misled  by  this  fallacy,  on  some  occasion  or 
another.  The  faithful  statements  of  travelers  and  histo- 
rians have  been  rejected  as  false,  on  no  better  grounds 
than  that  they  were  at  variance  with  the  views  of  those 
who  heard  or  read  them,  regarding  the  criterions  of 
truth. 

(A.)  Sophistical  distinction  is,  where  we  infer  that  the 
proposition  in  question  is  unproved,  because  it  appears 
to  differ,  in  some  respects,  from  that  which  has  been 
proved,  while  the  difference  is,  in  reality,  quite  immate- 
rial. When  the  question  has  been  proved  in  effect,  dif- 
ferenced in  the  mode  of  expression,  or  some  immaterial 
particular,  are  evidently  of  no  consequence.  This  fallacy 
is  sometimes  adopted  by  controversialists,  when  other 
arguments  have  failed. 

In  determining  whether  a  distinction  is  material,  we 
must  look  to  the  nature  of  the  inquiry,  and  see  how  it 
affects  the  point  in  question :  for  a  difference  which  may 
be  of  no  consequence  in  one  investigation  may  be  very 
important  in  another.  Thus,  the  particular  day  and 
hour  of  witnessing  a  phenomenon  may  be  of  little  conse- 
quence to  a  naturalist,  while  the  time  of  witnessing  an 
act  may  be  of  the  utmost  importance  on  a  criminal  trial. 

A  common  ^instance  of  this  sophism  is,  where  unim- 
peachable testimony,  regarding  an  immediate  compre- 
hension, is  rejected,  upon  the  ground  that  the  witness  is 
not  a  proper  judge  of  the  matter,  the  comprehension  be- 
ing confounded  with  inferences  that  may  be  drawn  from 
it,  which  are  a  very  different  thing.  Any  one  who  pos- 
sesses the  use  of  his  faculties,  may  be  quite  competent 
to  prove  what  he  apprehended,  although  it  may  require 
a  person  skilled  in  the  subject  to  draw  the  proper  infer- 
ences. 

3.  The  degree  of  probability  or  improbability  is  mate- 
rially mistaken,  forming  the  sophism  of  varying  proba- 
bility, of  which  there  are  four  varieties. 

(a.)  Exaggerating  probability  is,  where  we  infer  that 


SEC.  4.]  SOPHISMS  OF  PROBABILITY.  305 

the  degree  of  probability  is  much  greater  than  what  the 
proof,  in  reality,  establishes.  It  is  frequently  combined 
with  the  sophistical  leap :  a  low  probability  is  inferred 
to  be  very  high,  and  then  it  is  inferred  to  be  a  certainty. 

(b.)  Diminishing  probability  is,  where  we  infer  that 
the  probability  is  much  less  than  has  been  shown ;  and 
it  is  the  converse  of  the  preceding  fallacy. 

(c.)  Exaggerating  improbability  is,  where  an  improb- 
ability is  shown,  and  we  infer  that  it  is  much  greater 
than  the  reality.  It  is  the  converse  of  the  first. 

(c?.)  Diminishing  improbability  is,  where  an  improb- 
ability is  proved,  and  we  infer  that  it  is  much  less  than 
the  reality,  which  is  the  converse  of  the  third. 

These  fallacies  are  generally  combined  with  each  other, 
because  the  same  desire  which  leads  men  to  exaggerate 
one  view  of  the  subject  induces  them  to  diminish  the 
contrary :  and  they  are  of  frequent  occurrence,  because 
probability  does  not  generally  admit  of  accurate  meas- 
urement, and  its  real  character  is  not  easily  determined. 
A  common  instance  of  the  combination  is,  where  men 
embark  in  hazardous  undertakings  with  a  confident  ex- 
pectation of  success,  because  there  is  a  slight  probability 
in  its  favor,  which  they  magnify  into  a  very  great  prob- 
ability, while  they  equally  diminish  the  probabilities  of 
failure.  So,  favorite  opinions,  based  on  slight  probabili- 
ties, are  often  held  tenaciously,  as  being  extremely  prob- 
able, while  the  contrary,  and  really  more  probable,  opin- 
ions are  unhesitatingly  rejected. 

Fallacies  of  this  kind  may  arise  either  from  mistaking 
the  character  of  the  probability  in  the  first  instance,  or 
by  drawing  inferences  from  it,  and  then  overlooking  the 
character  of  the  premise. 

Sophisms  of  probability  are  very  prevalent,  because 
they  save  the  pain  of  suspense  and  the  labor  of  further 
investigation,  and  because  we  are  frequently  obliged,  in 
the  ordinary  business  of  life,  to  act  upon  strong  probabil- 
ities as  if  they  were  certainties.  Their  influence  is  often 
increased  by  the  Imagination  forming  vivid  and  agreea- 
ble pictures  of  what  we  desire  to  be  true,  and  equally 
vivid,  but  repulsive,  pictures  of  what  we  desire  to  be 
false.  These  erroneous  representations  excite  strong 
feelings,  which  withdraw  our  attention  from  the  weak 
points  of  the  case,  and  confine  it  to  what  makes  in  favor 
of  that  which  we  desire  to  be  true,  whence  the  fallacy  is 
frequently  unsuspected. 


306  ABERRANCIES.  [CHAP.  XIX. 

Different  kinds  of  this  class  of  fallacies  are  very  fre- 
quently combined  with  each  other.  We  adopt  one  prop- 
osition the  more  firmly,  because  the  contrary  is  deemed 
so  improbable,  and  conversely,  while  we  frequently  exag- 
gerate or  diminish  the  real  probabilities.  A  common  in- 
stance of  this  combination  is,  the  erroneous  conclusions 
we  form  regarding  our  future  lives  or  the  results  of  our 
undertakings  or  designs.  We  can  easily  find  facts  which 
establish  a  probability  that  we  shall  live  long,  succeed  in 
our  principal  undertakings,  and  secure  permanent  happi- 
ness, as  well  as  an  improbability  of  the  reverse.  We  are 
apt  to  overlook  the  possibly  stronger  probabilities  which 
lead  to  a  different  conclusion,  and  to  overcolor  both  sides 
of  the  picture. 

All  fallacies  of  this  class  are  frequently  combined  with 
paralogisms  of  comprehension,  signs  and  testimony,  with- 
out which  they  would  often  be  detected  by  a  full  and  ac- 
curate view  of  the  whole  case ;  but  when  we  overlook 
one  side  of  it,  and  form  an  erroneous  opinion  of  the  oth- 
er, that  may  appear  to  be  very  probable  which  we  should 
readily  perceive  to  be  the  very  reverse,  if  we  viewed  the 
matter  aright.  Those  who  purchased  lottery  tickets  of- 
ten thought  there  was  a  great  probability  that  they 
would  draw  a  high  prize,  although  it  was  quite  clear  to 
any  person  who  carefully  considered  the  matter  for  a  few 
seconds,  that  the  probability  was  all  the  other  way,  as 
the  high  prizes  were  very  rare,  and  only  an  exception  to 
the  rule.  So  many  satisfy  themselves  that  they  will  act 
prudently,  live  long,  resist  temptations  to  vice,  and  enjoy 
prosperity.  They  overlook  the  fact  that,  owing  to  their 
character  and  circumstances,  the  probability  is  all  the 
other  way :  and  the  events  turn  out  accordingly. 


CHAPTER  XIX. 

OF  ABEKRANCIES,   OB   FALLACIES    OF   IRRELEVANCY. 

1.  ABERRANCIES  OP  CONFUSION. — Nature  of  this  class  of  Fallacies. 
— (1)  Irrelevant  Illustration. — Legitimate  Object,  and  Abuse,  of 
Illustration. — (2)  Indefinite  Terms. — Proper  course  of  dealing  with 
this  Fallacy. — (3)  Irrelevant  Analogies. — Requisite  to  validity  of 
reasoning  from  Analogy. — Frequent  Combination. — (4)  Deciding 
by  Character. — Distinction. — Why  this  Aberrancy  prevalent. — 
Frequent  Combination. — (5)  Deciding  by  Consequences. — Truth 


SEC.  1.]          ABERKANCIES  OF  CONFUSION.  307 

preferable  to  Error. — Distinction. — (6)  Deciding  by  Motives. — Why 
these  no  Criterion  of  Truth. — Relation  of  Motives  to  Arguments. — 
Frequent  Combinations.  —  (7)  Deciding  by  Appearances.  —  Fre- 
quent effect  of  this  Aberrancy. — (8)  Irrelevant  Induction. — Why 
prevalent  in  Political  Discussions. — (9)  Irrelevant  Empiricism. — 
Requisite  to  establish  an  Empiricism. — Frequent  Combination. — 
(10)  Irrelevant  Objection. — Relation -of  Difficulties  to  sound  Argu- 
ments.— Criterions. — Caution. — Proper  mode  of  dealing  with  Ob- 
jections.— (11)  Irrelevant  Modification. — (12)  Homonymous  Ex- 
pressions.— Frequent  Combination. — (13)  Verbal  Illusion. — Why 
prevalent.  —  Distinction. — (14)  Illusive  Contradiction. — Frequent 
Combination. — (15)  Confounding  Means  and  End. 

IN  these  fallacies,  one  conclusion  is  assumed  to  be  tan- 
tamount to  another,  while  they  are  essentially  different, 
and  it  is  inferred  that  one  has  been  proved,  because  the 
other  may  have  been  proved.  The  following  enumera- 
tion includes  the  more  common : 

1.  Irrelevant  illustration  consists  in  confounding  mere 
illustrations  with  proofs.     The  legitimate  object  of  illus- 
trations is,  to  throw  light  on  a  proposition  which  is 
proved  and  directly  explained  independently.     Where 
all  our  knowledge  of  a  subject  is  derived  from  illustra- 
tions, we  generally  form  erroneous  conceptions  of  the 
thing  illustrated,  and  thus  think  we  know  what  we  only 
conceive.    Where  a  thing  entirely  unknown  is  illustrated 
by  something  familiar,  but  not  well  understood,  we  are 
apt  to  think  that  we  understand  both,  when  we  under- 
stand neither;  and  consequently  the  mere  illustration  is 
mistaken  for  a  proof  that  it  is  true,  while  no  legitimate 
proof  has  been  given. 

One  of  the  most  common  forms  of  this  fallacy  consists 
in  drawing  a  comparison  between  the  thing  to  be  proved 
and  something  else,  and  then  assuming  that  what  is  known 
to  be  true  of  the  latter  holds  equally  true  of  the  former. 
Thus,  communities  have  been  compared  to  individuals, 
and  it  was  then  assumed  that  they  all  have  a  period  of 
youth,  manhood,  old  age,  and  extinction. 

2.  Indefinite  terms  occurs  where  obscure,  ambiguous 
or  figurative  language  is  employed  in  such  a  manner  that 
it  is  impossible  to  determine  what  it  means ;  and,  there- 
fore, the  conclusion   actually  established  may  be  very 
wide  of  that  which  ought  to  be  proved,  if  anything  at  all 
has  been  established.     Where  an  essential  part  of  an  ar- 
gument consists  of  language  whose  exact  meaning  we 
cannot  ascertain,  it  is  impossible  to  determine  whether 


308  ABERRANCIES.  [CHAP.  XIX. 

any  conclusion  has  been  established :  for  the  objection- 
able part  may  involve  a  fallacy :  and  consequently  the 
whole  should  go  for  nothing,  so  far  as  proving  a  conclu- 
sion is  concerned. 

This  fallacy  abounds  in  various  treatises  on  mental 
science.  Loose  generalities  are  substituted  for  definite 
statements ;  and,  in  many  instances,  gross  absurdities  are 
veiled  under  misty  plausibilities. 

3.  Irrelevant  analogies  is,  where  an  analogous  conclu- 
sion is  proved,  which  is  assumed  to  establish  the  ques- 
tion, when,  in  reality,  it  does  not.  In  order  to  render 
such  argument  valid,  it  must  distinctly  appear  that  the 
two  cases  are  essentially  alike,  both  in  the  conclusion  and 
in  all  those  points  on  which  it  depends :  for,  if  they  differ 
in  these  respects,  other  resemblances  will  avail  nothing. 
It  is  not  sufficient  that  they  may  resemble  each  other  in 
these  respects :  it  must  appear  that  they  actually  do  so : 
else  the  analogy  may  fail  in  some  essential  point.  We 
may  err  by  assuming,  without  proof,  either  that  things 
which  are  alike  in  some  respects,  are  alike  in  others  also, 
or  that  things  which  differ  in  some  respects,  differ  in  oth- 
ers also. 

A  common  instance  of  this  fallacy  is,  proving  some- 
thing of  one  man,  and  then  inferring  that  this  holds  true 
of  another,  who  resembles  him  in  some  respects,  while 
there  is  no  proof  that  the  similarity  extends  so  far  as  it 
should  do,  in  order  to  render  the  reasoning  valid.  Thus, 
one  sick  person's  symptoms  may  resemble  those  of  an- 
other, while  their  diseases  may  differ  so  widely  that  what 
cured  one  will  only  injure  the  other.  So  it  has  been  ar- 
gued that  popular  education  must  be  injurious,  because, 
ff  a  horse  knew  enough,  he  would  throw  his  rider,  while 
it  is  not  shown  (and,  in  fact,  it  is  not  true)  that  the  rela- 
tion of  a  horse  to  his  owner  is  the  same  as  that  of  a  peo- 
ple to  their  rulers. 

To  this  fallacy  belongs  the  practice  of  applying  gen- 
eral maxims  to  cases  essentially  different  from  those  to 
which  they  properly  apply,  and  thus  drawing  erroneous 
inferences  regarding  the  case  in  question.  This  form  is 
often  combined  with  the  paralogism  of  misinterpretation, 
the  maxim  being  misunderstood,  as  well  as  misapplied. 
Other  instances  of  this  aberrancy  are — assuming  that  the 
future  will  be  like  the  past,  and  that  a  thing  will  never 
be,  because  it  has  been  shown  that  it  never  was — assum- 


SEC.  1.]  ABERRANCIES  OF  CONFUSION.  309 

ing  that  a  thing  must  be  useful  for  one  purpose,  because 
it  has  been  shown  to  be  useful  for  another — assuming 
that  a  thing  must  be  totally  bad,  and  should  never  be 
used,  because  it  is  liable  to  be  abused,  or  to  produce  evil 
— proving  that  a  thing  ought  to  be,  and  then  assuming 
that  it  actually  is,  or  that  it  ought  not  to  be  or  that  it 
would  be  useless,  and  then  assuming  that  it  is  not — that 
a  man  will  act  in  a  certain  way,  because  it  is  shown  that 
ordinary  prudence  requires  him  to  do  so — and  proving 
that  there  is  no  known  reason  why  a  conclusion  should 
not  be  true,  and  then  inferring  that  it  is  true,  while  there 
may  be  unknown  proof  that  it  is  false. 

The  aberrancy  is  frequently  combined  with  the  sophism 
of  false  cause,  by  assuming  that,  in  the  analogous  case,  a 
certain  phenomenon  resulted  from  a  cause  of  which,  in 
reality,  it  was  wholly  independent,  and  which  is  absent 
in  the  case  under  consideration. 

4.  Deciding  by  character  occurs  where  a  conclusion  is 
assumed  to  be  true,  because  it  is  shown  that  it  is  advo- 
cated by  good  men,  or  alleged  to  be  a  good  doctrine,  or 
it  is  assumed  to  be  false,  because  it  appears  that  it  is 
maintained  by  bad  men,  or  it  is  alleged  to  be  a  bad  doc- 
trine.   Good  men  have  often  advocated  errors,  while  bad 
men  have  held  many  opinions  which  were  correct :  and 
truth  has  frequently  been  decried  as  pernicious,  while 
error  has  been  upheld  as  fostering  virtue.     Hence  the 
truth  or  falsity  of  a  proposition  is  a  very  different  in- 
quiry from  that  of  the  character  of  its  advocates,  or  its 
alleged  nature ;  and  we  wander  from  the  point  when  we 
turn  to  discuss  them,  while  the  matter  before  us  is,  the 
professed  proof  that  the  proposition  is  true  or  false. 

In  many  cases  the  alleged  character  of  the  parties  and 
nature  of  the  proposition,  are  widely  different  from  the 
real,  so  that  the  argument,  besides  being  irrelevant,  is 
otherwise  fallacious.  Yet,  owing  to  the  influence  of  sev- 
eral strong  prejudices,  its  true  character  is  not  even  sus- 
pected. It  is  pleasing  to  indolence  to  think  that  it  can 
determine  the  truth  or  falsity  of  a  proposition  by  merely 
glancing  at  the  character  of  its  advocates,  which  is  as- 
sumed to  be  what  is  alleged  by  their  friends  or  enemies : 
and  it  is  soothing  to  the  feelings  to  conclude  that  a  doc- 
trine is  true,  when  it  flatters  avarice,  pride  or  vanity,  and 
false,  when  it  wounds  these  emotions. 

5.  Deciding  by  consequences  is,  where  certain  good 


310  ABEKRANCIES.  [CHAP.  XIX. 

consequences  are  held  to  flow  from  a  doctrine,  and  there- 
fore it  is  inferred  to  be  true,  or,  conversely,  it  is  inferred 
to  be  false,  because  certain  evil  consequences  are  alleged 
to  flow  from  it.  A  man  sometimes  finds  that,  if  a  cer- 
tain conclusion  is  true,  he  is  bound  to  abandon  some  fa- 
vorite practice,  or  relinquish  some  lucrative  occupation ; 
and,  therefore,  he  is  strongly  disposed  to  reject  such  a 
doctrine,  though  it  may  have  been  proved  quite  conclu- 
sively, and,  in  fact,  the  difficulty  which  he  encounters  is 
in  favor  of  the  disagreeable  conclusion.  That  it  should 
militate  against  a  vicious  practice  or  a  pernicious  pur- 
suit, rather  proves  it  true  than  otherwise.  Yet  the  vic- 
tim is  very  unwilling  to  believe  the  bitter  truth,  although, 
in  reality,  the  sooner  he  does  so,  the  better  for  his  own 
permanent  welfare. 

Truth  is  always  more  favorable  to  happiness,  in  the 
long  run,  than  error,  although  it  may  occasion  some  tem- 
porary pangs,  or  deprive  us  of  some  fleeting  or  fancied 
good.  The  world  has  yet  to  see  the  first  instance  in 
which  a  person  did  not  gain  much  more  than  he  lost  by 
discarding  error  and  adopting  truth,  while  there  are  in- 
numerable instances  in  which  men  clung  to  errors,  under 
the  belief  that  the  contrary  doctrines  were  inimical  to 
their  happiness,  when,  in  reality,  those  errors  destroyed 
their  happiness,  while  the  adoption  of  truth  would  have 
secured  an  opposite  result.  We  should,  therefore,  ad- 
dress ourselves  fearlessly  to  the  proofs,  while  we  are  in- 
quiring whether  a  proposition  is  true  or  false.  Its  bear- 
ings on  our  future  condition  is  a  distinct  question,  which 
should  never  be  allowed  to  interfere  with  the  former. 

To  this  fallacy  belongs  the  practice  of  pronouncing  on 
the  wisdom  or  folly  of  a  certain  course,  according  to  the 
subsequent  results.  These  may  depend  on  circumstances 
which  no  human  foresight  could  anticipate,  and  make  a 
course  afterwards  seem  foolish  which  previously  appear- 
ed the  most  eligible.  On  the  other  hand,  a  very  silly 
scheme  sometimes  produces  favorable  results,  owing  to 
accidental  circumstances,  which  were  not  foreseen,  and 
of  which  there  was  very  little  probability. 

6.  Deciding  by  motives  occurs  where  the  conclusion  is 
decided  according  to  the  motives  which  are  alleged  to 
actuate  the .  advocate.  A  man  may  advocate  the  cause 
of  truth  from  bad  motives,  or  that  of  error  from  the  re- 
verse, and  hence  motives  are  no  criterion  of  the  conclu- 


SEC.  1.]  ABEKKANCIES  OF  CONFUSION.  311 

sion.  In  examining  a  man's  general  character,  or  the 
bearings  of  an  act  which  he  has  done,  the  motives  which 
influenced  him  may  form  a  very  pertinent  and  important 
subject  of  inquiry:  but  the  truth  or  falsity  of  a  propo- 
sition which  he  advocates  is  a  very  dhTerent  matter.  A 
conclusive  argument  is  not  a  whit  invalidated  by  being 
urged  from  bad  motives,  while  a  worthless  argument  is 
not  in  tjie  least  aided  by  the  good  motives  of  its  pleader. 

A  common  instance  of  this  aberrancy  is,  assuming  that 
an  argument  must  be  worthless,  because  it  is  inconsist- 
ent with  some  other  opinion  expressed  by  the  advocate, 
as  if  a  good  argument  was  refuted  by  the  fact  that  its 
inaintainer  had  formerly  employed  a  bad  one,  or  express- 
ed himself  differently  on  the  same  subject. 

This  fallacy  is  often  combined  with  those  of  deciding 
by  consequences  and  character.  Certain  bad  conse- 
quences are  alleged  to  follow  from  the  conclusion,  and  it 
is  asserted  that  the  advocate  must  be  a  bad  man,  and 
therefore  he  must  be  influenced  by  bad  motives,  and 
therefore  the  conclusion  must  be  false,  or  conversely. 
Possibly  the  supposed  consequences  are  wholly  imag- 
inary, or  the  individual  may  not  see  that  they  follow. 
Many  hold  opinions  that  really  imply  consequences  which 
they  neither  see  nor  admit.  Doctrines  produce  their  le- 
gitimate consequences  in  the  long  run,  on  the  majority 
of  those  who  embrace  them :  but  they  do  not  always  do 
so  in  the  first  instance,  or  in  every  individual  case. 

Not  unfrequently  the  aberrancy  is  combined  with 
sophisms  of  causation  and  probability.  The  individual 
has,  in  reality,  acted  from  several  different  motives,  or 
those  alleged  are  only  probable,  or  perhaps  wholly  im- 
aginary, so  that,  in  fact,  no  conclusion  whatever  is  proved. 

7.  It  is  shown  that  there  are  several  indications  which 
go  to  prove  a  certain  conclusion,  and  it  is  inferred  that 
it  is  absolutely  proved,  forming  the  aberrancy  of  decid- 
ing ly  appearances.  It  often  escapes  detection,  partly 
owing  to  the  influence  of  strong  prejudices,  and  partly 
from  the  indications  establishing  a  probability  in  favor 
of  the  conclusion. 

Instances  of  this  fallacy  occur  where  it  is  inferred  that 
a  certain  person  is  a  good  man,  because  it  has  been  shown 
that  he  professes  to  be,  and  is  generally  considered  such, 
and  that  he  has  performed  some  good  actions,  while  a 
wider  and  closer  investigation  would  prove  the  reverse. 


312  ABERRANCIES.  |_U*L\p.  XIX. 

So  it  is  often  inferred  that  a  man  is  a  bad  character,  be- 
cause he  has  been  charged  with  having  committed  wick- 
ed acts,  when,  in  truth,  the  charge  is  quite  groundless, 
and  the  acts  were  harmless  and  proper;  and,  even  if 
they  were  not,  they  would  not  prove  the  conclusion. 
Particular  actions  do  not  prove  general  character,  any 
more  than  the  latter  proves  the  former ;  nor  does  the  per- 
formance of  certain  virtues  and  abstinence  from  certain 
vices,  prove  a  man  virtuous. 

8.  Irrelevant  induction  is,  where  a  thing  is  proved  to 
hold  true  of  numerous  cases,  and  this  is  assumed  to  prove 
that  it  holds  true  of  a  whole  class,  when  there  is  no  proof 
to  warrant  such  an  inference,  which  is  justified  only  by 
facts  that  logically  involve  it.     Instances  of  this  aber- 
rancy occur  even  in  Mathematics,  as  where  the  binomial 
theorem  had  been  assumed  to  hold  true  generally  simply 
because  it  did  so  in  many  cases.     It  is  very  common  in 
political  discussions,  since  parties  readily  assume  that 
what  has  been  true,  in  several  cases,  will  always  hold 
true,  where  the  assumption  helps  them  in  defending  a 
weak  position. 

9.  Irrelevant  empiricism  is  where  a  thing  is  proved  of 
several  individuals,  and  it  is  then  assumed  to  apply  to 
others,  of  which  it  has  not  been  proved,  and  of  which, 
possibly,  it  does  not  hold  true.     The  satellites  of  the 
Earth,  Jupiter  and  Saturn,  all  revolve  round  their  prima- 
ries from  west  to  east ;  but  some  of  Saturn's  revolve  in 
the  contrary  direction.     To  establish  an  empiricism,  it  is 
requisite  that  every  individual  object  embraced  in  the 
conclusion,  should  have  been  examined,  and  found  to  pos- 
sess the  attribute  in  question. 

The  two  preceding  aberrancies  are  sometimes  com- 
bined with  each  other,  and  with  paralogisms  of  compre- 
hension. While  the  proposition  in  question  is  professed 
to  have  been  established  as  an  induction,  a  wider  and 
more  accurate  observation  would  show  that  it  is  not  true 
even  empirically.  Phrenology  furnishes  a  good  instance 
of  this  combination.  Not  only  do  its  advocates  fail  to 
show  that  the  alleged  conformity  between  certain  forms 
of  the  head  and  certain  mental  characteristics  hold  true 
generally,  but  they  fail  to  prove  that  it  has  been  hitherto 
found  to  hold  true ;  and  careful  observation  will  readily 
show  that  no  such  conformity  exists,  and  that  the  cases 
of  nonconformity  are  much  more  numerous  than  those 
of  casual  conformity. 


SEC.  4.]          ABERRANCIES  OF  CONFUSION.  313 

10.  Irrelevant  objection  occurs  where  it  is  shown  that 
the  proposition  in  question  is  liable  to  certain  objections, 
or  that  difficulties  attend  its  reception,  whence  it  is  in- 
ferred to  be  false,  while,  in  reality,  those  difficulties  nei- 
ther disprove  the  conclusion  nor  invalidate  the  argu- 
ments by  which  it  is  established.  The  alleged  doubts 
or  difficulties  are  generally  founded  on  the  objector's 
vague  or  erroneous  views  of  the  whole  subject,  or  at 
least  of  an  essential  part  of  it,  and  consequently  possess 
no  real  weight.  Difficulties  attend  every  department  of 
human  knowledge :  but  they  do  not  affect  conclusive 
proofs. 

Sometimes  the  objection  applies  only  to  a  misrepre- 
sentation of  the  proposition  in  question,  made  by  a  party 
who  does  not  rightly  understand  it,  and  not  to  the  real 
question.  It  is  not  uncommon  for  persons  to  defend  doc- 
trines which  they  do  not  rightly  understand ;  and,  there- 
fore, we  should  first  ascertain  what  a  proposition  really 
is,  before  we  regard  objections,  which  may  possibly  ap- 
ply only  to  what  it  is  erroneously  represented  to  be. 

A  common  instance  of  this  aberrancy  is,  where  a  prop- 
osition is  argued  to  be  false,  because  it  is  alleged  to  be 
inconsistent  with  some  known  fact,  or  to  lead  necessarily 
to  some  erroneous  inference,  when,  in  reality,  such  alle- 
gations are  quite  irrelevant.  Sometimes  they  are  false, 
and,  in  other  cases,  although  true,  they  are,  in  reality, 
quite  consistent  with  the  proposition  in  question. 

A  sound  argument  can  no  more  be  inconsistent  with 
any  truth  than  one  truth  can  be  incompatible  with  an- 
other. If,  therefore,  the  objection  conclusively  proves 
that  the  proposition  in  question  cannot  possibly  be  true, 
it  is  sound,  but  otherwise  not.  It  avails  nothing  that  it 
establishes  a  strong  probability  against  it,  if  this  is  rebut- 
ted by  conclusive  evidence,  or  even  by  a  stronger  prob- 
ability on  the  other  side.  If  the  proof  in  favor  of  the 
proposition  is  conclusive,  every  objection  must  evidently 
be  futile,  and  should  go  for  nothing. 

In  no  case  should  we  reject  as  invalid  a  proof  which 
appears  to  be  quite  the  reverse,  till  we  have  given  or  ob- 
tained a  demonstration  of  its  fallaciousness.  Sometimes 
we  may  think  this  is  attainable,  when  a  serious  attempt 
to  find  it  would  show  us  that  the  objection  is  worthless, 
and  the  proof  irrefragable.  It  frequently  happens  that 
the  proof  exhibits  something  which  is  objectionable,  but 
O 


314  ABEREANCIES.  [CHAP.  XIX. 

which  does  not  affect  its  substantial  validity,  as  where 
something  false  is  assumed  in  an  argument  which  does 
not  affect  its  soundness,  and  may,  in  fact,  be  a  mere  illus- 
tration. Yet  the  objector  is  apt  to  fasten  on  the  flaw, 
and  hold  it  forth  as  conclusive.  We  should,  therefore, 
observe  the  relation  of  the  objectionable  part  to  the 
whole  proof,  and  ascertain  whether  the  objection  is  not 
irrelevant,  even  admitting  that  its  primary  premises  are 
quite  true. 

11.  Irrelevant  modification  consists  in  proving  a  prop- 
osition which  is  a  modification  of  the  one  in  question, 
but  yet  materially  different.     A  common  instance  of  it 
is,  where  a  conclusion  is  proved  conditionally,  when  it 
ought  to  have  been  proved  absolutely.     Thus  jurists 
have  sometimes  professedly  shown  that  a  particular  form 
of  government  was  the  best  for  a  particular  nation,  and 
then  assumed  they  had  proved  it  is  the  best  for  every 
nation.     So  it  is  sometimes  assumed  that  a  certain  regi- 
men or  medical  treatment  is  best  for  everybody,  because 
it  has  been  shown  to  be  the  best  for  persons  of  a  partic- 
ular constitution ;  and  many  lives  have  been  thus  lost. 
Another  instance  is,  showing  that  a  certain  law,  institu- 
tion, or  custom  had  a  rational  origin,  and  then  assuming 
this  as  proving  that  it  is  good  universally,  while,  in  fact, 
it  may  be  very  bad  when  circumstances  have  greatly 
changed. 

12.  Homonymous  expressions  consists  in  proving  a 
proposition  which  sounds  very  like  the  one  in  question, 
and  may  be  readily  mistaken  for  it,  while  it  is  essentially 
different.     It  is  favored  by  the  fact  that  many  words  and 
expressions  are  very  similar  in  sound,  but  yet  materially 
different  in  signification.     A  man  may  do  many  foolish 
things  without  being  a  fool,  and  many  good  things  with- 
out being  good.     This  aberrancy  is  often  combined  with 
the  preceding;  and  the  combination  occurs  not  unfre- 
queutly  in  public  addresses.     Thus,  a  speaker  proves  that 
everybody  within  a  certain  narrow  circle  thinks  or  does 
so  and  so ;  and  this  is  assumed  as  proving  that  all  man- 
kind do  so. 

13.  Verbal  illusion  occurs  where  the  name  of  a  thing, 
or  a  definition  of  it,  is  given,  and  this  is  assumed  to  be 
tantamount  to  communicating  or  acquiring  a  knowledge 
of  its  nature.     We  are  very  ready  to  adopt  this  fallacy, 
because  the  name  is  apt  to  be  confounded  with  the  char- 


SEC.  1.]          ABEKKANCIES  OF  CONFUSION.  315 

acter,  and  it  is  so  much  easier  to  master  the  former,  or 
read  a  definition,  than  to  acquire  a  real  knowledge  of  the 
latter.  Thus,  many  have  thought  that  they  had  acquired 
a  good  knowledge  of  Botany,  when  it  went  no  farther 
than  to  enable  them  to  tell  the  name  of  a  genus.  So 
teachers  have  often  thought  that  they  communicated  to 
their  pupils  a  knowledge  of  the  subject,  when  they  only 
taught  them  words  whose  real  import  they  never  under- 
stood. Words  can  convey  no  real  instruction  unless 
their  import  is  properly  understood  and  remembered, 
which  is  a  very  different  thing  from  merely  hearing  or 
reading  and  repeating  them. 

14.  Illusive  contradiction  consists  in  confounding  the 
contrary  of  a  proposition  with  its  contradictory,  and  it  is 
inferred  that  it  is  true,  because  its  contrary  is  shown  to 
be  false.  Thus,  it  is  often  assumed  that  a  thing  is  bad, 
because  it  has  been  proved  that  it  is  not  good,  or  that  a 
certain  line  of  conduct  is  commendable,  because  the  con- 
trary course  is  reprehensible,  as  if  the  sky  must  be  white, 
because  it  is  not  black.  So  it  is  often  assumed  that  a 
man  is  austere,  because  he  is  not  gay,  or  penurious,  be- 
cause he  is  not  extravagant,  or  rash,  because  he  is  not 
timid,  and  so  forth. 

The  fatalists'  argument  is  a  notable  example  of  this 
aberrancy.  "A  thing  will  either  happen  or  not,"  and 
this  is  confounded  with  "  happening  if  I  act  thus,  and  not 
happening  if  I  act  otherwise."  When  a  man's  house  is 
on  fire,  the  real  question  is,  whether  his  efforts  will  affect 
the  result ;  and  this  is  not,  in  the  least  met,  by  saying 
that  it  is  destined  either  to  burn  or  not  to  burn,  which 
is  only  saying  that  it  either  will  burn  or  it  will  not,  a 
self-evident  truth,  indeed,  but  quite  irrelevant. 

Another  instance  of  this  fallacy  is,  confounding  "  be- 
lieving" with  "not  disbelieving."  As  we  must  either 
believe  or  not  believe,  it  is  assumed  that  we  believe 
everything  which  we  do  not  formally  disbelieve,  whereas 
we  have  no  real  belief  or  disbelief  in  a  thing  of  which  we 
are  ignorant.  Confidence  in  a  man's  veracity  is  a  very 
different  thing  from  believing  his  opinions,  which  we 
cannot  do  till  we  know  what  they  are. 

This  aberrancy  is  frequently  combined  with  the  soph- 
ism of  false  connection.  Because  a  conclusion  does  not 
follow  from  the  premises,  it  is  inferred,  not  only  that  it 
is  false,  but  that  the  contrary  is  true.  Thus,  a  contro- 


316  ABEKRANCIES.  [CHAP.  XIX. 

versialist  often  assumes  that  his  own  position  is  proved, 
because  he  has  detected  a  flaw  in  some  reasoning  em- 
ployed to  prove  the  contrary  conclusion.  The  compound 
fallacy  is  of  this  sort :  "  this  reasoning  fails  to  prove  that 
crows  are  black;  therefore  they  are  white."  To  war- 
rant us  in  receiving  a  proposition  as  true,  it  is  not  suffi- 
cient to  disprove  certain  arguments  employed  to  prove 
the  contrary  doctrine :  we  must  have  positive  and  con- 
clusive proof  that  it  is  true.  For  the  contrary  proposi- 
tion may  be  provable  by  other  arguments,  or  both  prop- 
ositions may  be  false. 

15.  Confounding  means  and  end  consists  in  proving 
that  the  end  or  object  to  be  effected  by  certain  means, 
is  good,  and  then  assuming  that  the  latter  are  good.  A 
proper  end  may  be  sought  by  wrong  means,  of  which 
numerous  cases  are  found  both  in  History  and  common 
life.  Consequently  the  character  of  the  means  must  be 
ascertained,  on  other  grounds  than  the  goodness  of  the 
end.  In  many  instances,  the  object  is  really  bad,  and 
only  supposed  to  be  good :  but  the  fallacy  is  not  the  less 
complete,  even  where  it  is  really  good.  Fraud  is  unjus- 
tifiable when  it  is  employed  to  propagate  truth,  as  well 
as  when  it  is  used  to  sustain  error. 

§  2.  ABERRANCIES  OF  APPEALS  TO  AUTHORITY. — Nature  of  this 
Class. — (1)  Universal  Belief. — Why  not  conclusive  Proof. — (2) 
General  Belief. — (3)  Conflicting  Opinions. — Its  Foundations. — 
(4)  Modern  Opinions. — Why  not  Proof. — (5)  Sages'  Opinions. — 
Distinction. —  Sources  of  Error.  —  Frequent  Combination. —  (G) 
Many  Arguments. — Distinction. — Various  Forms. — (7)  Pretended 
Refutation. — Proper  mode  of  dealing  with  Refutations. — (8)  Ir- 
relevant Admission. — Its  Charactei'istic. — Frequent  Effect  of  it. 
— With  what  often  combined. — Why  Aberrancies  of  this  class  are 
common. — How  to  be  avoided. — Important  Distinctions. 

In  this  class  of  aberrancies,  it  is  shown  by  others,  or 
is  found  by  ourselves,  that  certain  persons  have  believed 
the  proposition  in  question,  which  is  considered  tanta- 
mount to  proving  that  it  is  true,  while,  for  anything  that 
appears  to  the  contrary,  it  may  be  false.  The  following 
are  the  most  common  kinds. 

1.  Universal  belief  occurs  where  a  conclusion  is  either 
assumed  to  be  true,  because  it  is  found  that  all  mankind 
have  believed  it,  or  it  is  assumed  that  it  must  be  false, 
because  it  appears  that  all  mankind  have  disbelieved  it. 
There  may  be  various  Sources  of  illusion,  common  to  all 


SEC.  2.]  APPEALS  TO  AUTHORITY.  317 

mankind ;  and  hence  universal  belief  is  by  no  means  a 
conclusive  proof  that  a  proposition  is  true.  All  mankind, 
for  many  ages,  believed  things  self-evidently  or  demon- 
strably  false,  and  rejected  as  false  things  self-evidently 
or  demonstrably  true.  We  uniformly  believe  that  our 
dreams  are  real,  till  we  awake,  when  we  discover  the 
contrary.  So  it  was  universally  believed,  for  many  ages, 
that  the  Sun,  Moon,  and  stars  revolve  daily  round  the 
Earth,  while  the  doctrine  that  the  Sun  is  at  rest,  and  the 
Earth  in  motion,  wTas  rejected  as  an  absurdity. 

2.  General  belief  is,  where  we  infer  that  a  proposition 
is  true,  because  it  appears  that  the  great  majority  of  man- 
kind have  believed  it,  in  all  ages.    If  universal  belief  does 
not  prove  a  proposition  true,  much  less  will  the  belief  of 
a  majority  only,  especially  when  we  consider  how  fre- 
quently and  readily  opinions  are  adopted  without  any 
proper  investigation.     It  has  been  a  generally  received 
opinion  that  seeds  germinate  more  quickly  during  the 
crescent  Moon  than  when  it  is  in  the  wane ;  yet  a  very 
slight  investigation  shows  that  it  is  quite  groundless. 

3.  Conflicting  opinions  consists  in  inferring  that  a 
proposition  is  doubtful,  because  it  appears  that  different 
opinions  are  held  regarding  it,  when  its  truth  may  have 
been  conclusively  established.     This  aberrancy  proceeds 
on  the  absurdities  that  any  man's  views  are  as  likely  to 
be  correct  as  any  other's,  and  that  we  cannot  be  certain 
a  conclusion  is  true,  as  long  as  there  is  anybody  so  ig- 
norant, indolent,  stupid  or  prejudiced  as  to  reject  it. 
Where  we  have  unquestionable  proof  that  it  is  true,  the 
opinions  of  such  persons  to  the  contrary  are  entitled  to 
no  weight. 

4.  It  is  inferred  that  a  proposition  is  true  or  false  be- 
cause it  appears  to  be  deliberately  held  or  rejected  by 
the  men  of  the  present  day.    This  we  call  the  aberrancy 
of  modern  opinions.    No  age  is  exempt  from  error ;  and 
it  has  sometimes  happened  that  old  opinions  have  been 
re-adopted,  on  good  grounds,  after  having  been  long  re- 
jected.   The  astronomical  opinions  of  Aristarchus  of  Sa- 
mos  were  rejected  by  all  astronomers,  for  nearly  two 
thousand  years ;  yet  they  have  been  demonstrated  to  be 
correct. 

5.  Sages'*  opinions  occurs  where  it  appears  that  wise 
or  distinguished  men  held  a  certain  opinion,  and,  there- 
fore, it  is  inferred  to  be  correct,  although  there  may  be 


318  ABERRANCIES.  [CHAP.  XLX. 

positive  proof  to  the  contrary.  History  furnishes  innu- 
merable instances  in  which  such  men,  who  were  consid- 
ered guides,  held  conflicting  views,  or  opinions  wrhich 
were  afterwards  demonstrated  to  be  quite  erroneous. 
We  must  distinguish  between  testimony,  regarding  mat- 
ters which  can  be  certainly  known,  and  mere  opinions, 
which  are  generally  based  only  on  probabilities.  An 
unimpeachable  witness  may  be  safely  believed,  when  he 
relates  something  within  his  knowledge:  but  this  does 
not,  in  the  least,  warrant  us  in  adopting  his  mere  opin- 
ions as  ascertained  truths,  especially  where  there  may  be 
accessible  proofs  that  they  are  quite  erroneous. 

Distinguished  men  are  sometimes  as  much  under  the 
influence  of  prejudices  as  any  others :  and  a  person  of  or- 
dinary abilities,  who  examines  a  subject  carefully  and  im- 
partially, will  often  arrive  at  truth,  where  men  of  greater 
talents  err,  through  inattention,  haste  or  prejudice.  A 
conceit  of  their  own  abilities  has  often  injured  such  per- 
sons, in  the  pursuit  of  truth,  more  than  their  intellectual 
superiority  benefited  them.  In  all  the  most  important 
investigations,  the  great  requisites  are,  attentive,  unprej- 
udiced and  persevering  examination,  with  a  fixed  desire 
to  discover  truth.  For  the  want  of  these,  neither  a  great 
reputation  nor  brilliant  talents  will,  in  the  least,  compen- 
sate. 

This  aberrancy  is  often  combined  with  those  of  mis- 
comprehension and  misinterpretation  of  language.  A 
person's  real  views  are  mistaken  or  misinterpreted ;  and 
then  his  authority  is  adduced  to  support  opinions  which 
he  never  held.  Thus,  the  usages  of  our  ancestors  are  oft- 
en quoted  to  support  or  oppose  some  proposed  change. 
As  our  ancestors'  circumstances  were  very  different  from 
ours,  their  actual  usages  form  no  criterion  of  what  they 
would  have  done,  in  our  circumstances.  It  is  not  likely 
that  our  pagan  forefathers  would  discard  revealed  relig- 
ion, if  placed  in  our  circumstances.  Time  produces  many 
changes,  so  that  what  is  eligible  in  one  generation  may 
be  the  reverse  in  another.  So  it  is  frequently  maintain- 
ed that  the  experience  of  competent  judges  has  already 
decided  the  question,  when  the  thing  really  experienced 
is  essentially  different.  It  was  once  believed  the  expe- 
rience of  intelligent  surgeons  proved  that  scalding  oil  is 
useful  in  dressing  wounds,  whereas  it  is  now  well  known 
that  it  proves  the  reverse. 


SEC.  2.]  APPEALS  TO  AUTHORITY.  319 

6.  It  appears  that  the  point  in  question  is  sustained  by 
various  arguments,  whence  it  is  inferred  that  it  is  duly 
proved,  forming  the  aberrancy  of  many  arguments.  No 
number  of  arguments  can  prove  a  conclusion,  as  long  as 
every  one  of  them  is  invalid ;  and  many  such  have  been 
employed  to  prove  false  conclusions,  of  which  the  Ptole- 
maic Astronomy  and  the  Aristotelian  philosophy  furnish 
various  instances.  We  should  remember  that,  as  in  the 
case  of  witnesses,  it.  is  the  weight  of  arguments  that 
avails,  and  not  their  number :  while  one  conclusive  argu- 
ment proves  a  proposition,  beyond  any  reasonable  doubt, 
a  thousand  fallacious  arguments  establish  nothing.  Yet 
this  fallacy  has  often  produced  conviction,  because  its 
victims,  while  possibly  distrustful  of  the  particular  argu- 
ment under  consideration,  relied  on  the  combined  force 
of  the  others,  and  so  on,  in  an  endless  round. 

I7.  Pretended  refutation  is,  where  an  argument  and  the 
conclusion  based  on  it,  are  rejected,  because  they*fcave 
been  professedly  refuted,  when,  in  reality,  the  refutation 
is  fallacious.  It  is  often  added  that  the  conclusion  in 
question  is  an  exploded  opinion,  which  nobody  but  very 
ignorant  or  silly  persons  now  hold.  In  many  instances, 
the  argument  is  grossly  misrepresented,  and  nothing  is 
refuted  but  what  was  never  held,  or  something  essential- 
ly diiferent  from  the  matter  in  question.  Sometimes  the 
refutation  is  directed  against  the  fallacious  arguments  of 
an  ignorant  or  incompetent  advocate,  and  never  touches 
the  real  proof.  At  other  times,  the  main  parts  of  the  ar- 
gument are  overlooked,  while  a  few  immaterial  errors  are 
detected ;  and  this  is  assumed  to  be  a  complete  refuta- 
tion. Consequently  we  should  examine  the  argument, 
and  compare  it  carefully  with  the  professed  refutation, 
before  we  receive  the  latter  as  of  any  weight.  Error 
never  appears  more  clearly  in  its  true  character,  than 
when  it  has  had  a  fair  hearing  and  a  searching  examina- 
tion. 

8.  It  appears  that  a  certain  conclusion  follows  from 
premises  admitted  by  a  party  who  denies  it,  whence  it  is 
inferred  that  it  must  be  true,  forming  the  aberrancy  of 
irrelevant  admission.  It  is  perfectly  fair  to  argue  that 
a  man  is  bound  to  admit  a  conclusion  necessarily  implied 
in  premises  which  he  admits  or  believes :  the  fallacy  lies 
in  assuming  that  the  conclusion  has  been  established  ab- 
solutely, while  the  admitted  premises  may  be  false.  If  a 


320  ABEKKANCIES.  [CHAP.  XIX. 

man  admits  that  the  main  object  of  public  punishments 
is,  the  reformation  of  the  offender,  he  admits,  fey  neces- 
sary implication,  that  capital  punishments  are  wrong ; 
but  this  admission  is  false,  the  reformation  of  the  offend- 
er being  only  a  secondary  object  in  public  punishments, 
although  it  is  often  the  sole  object  of  private  chastise- 
ment. 

This  fallacy  has  sometimes  confirmed  controversialists 
in  their  errors.  The  opposite  party  made  admissions 
which  proved  their  tenets ;  and  they  never  saw  or  sus- 
pected that  those  admissions  were  unwarrantable.  The 
aberrancy  is  often  combined  with  the  paralogism  of  mis- 
representing testimony.  A  man's  admission  or  expressed 
belief  is  misrepresented ;  and  then  it  is  assumed  that  the 
consequences  necessarily  implied  in  the  misrepresentation 
are  established  absolutely  and  conclusively. 

Fallacies  of  appeals  to  authority  are  very  prevalent,  on 
account  of  the  greater  ease  and  pleasure  with  which  a 
conclusion  can  generally  be  settled  by  such  appeals,  in- 
stead of  being  decided  by  a  proper  investigation  of  proofs, 
while  numerous  strong  prejudices  often  intervene,  and 
rivet  the  error.  The  proper  course  is,  to  ascertain  wheth- 
er there  is  conclusive  proof  of  the  truth  of  the  proposition 
in  question.  If  there  be,  it  must  stand,  although  high 
authority  reject  it :  if  there  be  not,  it  has  no  good  title 
to  be  classed  with  cognitions,  and  it  may  possibly  be 
false,  no  matter  who  believe  the  contrary. 

Preponderating  authority  may  be  very  properly  made 
our  guide  where  certainty  is  unattainable,  and  we  can 
arrive  only  at  probabilities :  but  mere  human  belief  can 
never  prove  any  proposition,  because  it  is  never  exempt 
from  error.  We  should  not,  therefore,  confound  the  ques- 
tion whether  the  proposition  under  consideration  is  true, 
with  the  very  different  inquiry  what  others  have  thought 
of  it,  as  is  generally  done  by  those  who  are  misled  by  this 
class  of  fallacies.  To  establish  or  refute  a  proposition  by 
legitimate  proof,  is  a  very  different  thing  from  showing 
that  men  have  believed  it  to  be  true  or  false. 

§  3.  ABERRANCIES  OP  APPEALS  TO  DESIRES. — Nature  of  this  Class. 
— (1)  Inferring  the  Agreeable. — Its  operation. — Distinction. — (2) 
Rejecting  the  Disagreeable. — Frequent  Practices. — Sneers  and  Rid- 
icule.— Distinction. — Combination. — How  these  Fallacies  are  fos- 
tered.— Their  two-fold  Origin. — Their  Influence  and  general  Char- 
acter.— How  combined. — How  they  may  be  avoided. 


SEC.  3.]  APPEALS  TO  DESIRES.  321 

Here  the  proposition  in  question  excites  strong  emo- 
tions or  sensations,  whence  it  is  inferred  that  it  is  true  or 
false,  while  its  real  character  is  not  properly,  if  at  all,  in- 
vestigated. Of  this  class  there  are  two  kinds. 

1.  A  conclusion  becomes  very  agreeable,  and  it  is  thence 
inferred  that  it  is  true,  forming  the  aberrancy  of  infer- 
ring the  agreeable.     Here  the  facts  or  arguments  that 
militate  against  the  conclusion  are  seldom  considered 
with  any  degree  of  attention :  they  are  sometimes  dis- 
missed with  a  sneer  or  a  sarcasm ;  and  sometimes  they 
are  not  noticed  at  all.     In  many  cases  the  proposition  in 
question  is  merely  characterized  by  eulogistic  epithets, 
and  its  adherents  are  called  by  corresponding  terms, 
whence  it  is  assumed  to  be  true.    There  is  no  error  to 
which  the  strongest  terms  of  commendation  cannot  be 
easily  applied,  while  there  is  no  truth  to  which  the  most 
opprobrious  epithets  cannot  be  applied,  with  equal  fa- 
cility. 

A  common  and  pernicious  instance  of  this  fallacy  is, 
inferring  that  the  course  which  promises  present  enjoy- 
ment and  immunity  from  present  pain,  is  the  best,  when 
the  case  may  be  far  otherwise ;  and  thus  many  have  sac- 
rificed their  future  all  for  a  fleeting  present  gratification. 
The  notion  of  enduring  present  pain,  or  foregoing  pres- 
ent pleasure,  is  so  disagreeable  that  they  assume  the  fu- 
ture is  of  less  importance ;  and  the  excitement  withdraws 
the  attention  from  a  careful  consideration  of  it. 

Another  common  instance  is,  where  it  appears  that  we 
shall  gain  wealth,  ease,  distinction,  the  approbation  of 
friends,  or  the  patronage  of  the  powerful,  if  we  believe 
the  proposition  in  question,  and  it  is  assumed  that,  there- 
fore, it  is  true.  Although  such  inducements  tend  to  pro- 
duce conscious  hypocrisy,  rather  than  real  belief,  yet  it 
has  frequently  caused  conviction,  the  prejudices  excited 
having  confined  the  attention  to  one  aspect  of  the  sub- 
ject, and  concealed  its  true  bearings.  But  the  advant- 
ages to  be  derived  from  believing  a  proposition  are  a  to- 
tally different  thing  from  its  truth  or  falsity,  with  which 
they  ought  never  to  be  confounded. 

2.  Something  appears  which  renders  a  conclusion  dis- 
agreeable, whence  it  is  inferred  to  be  false,  forming  the 
aberrancy  of  rejecting  the  disagreeable.     It  is  simply  the 
converse  of  the  preceding  fallacy ;  and  the  same  remarks 
apply  to  both,  by  merely  reversing  the  terms.     Some- 

O  2 


322  ABEKKANCIES.  [CHAP.  XIX. 

times  the  proposition  in  question  is  held  up  to  ridicule, 
and  called  by  offensive  or  contemptuous  epithets,  and 
then  it  is  assumed  to  have  been  proved  false,  a  course 
which  has  often  imposed  on  the  unthinking,  who  seem  to 
believe  that  an  argument  can  be  refuted  by  a  simple  ex- 
clamation of  scorn  or  ridicule. 

The  strength  of  the  language  in  which  the  conclusion 
is  decried,  generally  increases  as  the  evidence  of  its  truth 
becomes  clearer.  When  a  man  is  too  prejudiced  to  yield 
to  testimony  or  arguments,  which  prove  that  his  conduct 
or  opinions  are  wrong,  he  frequently  stifles  his  convic- 
tions or  suspicions  by  a  free  use  of  ridicule  or  abusive 
language.  But,  for  the  reason  already  mentioned,  these 
have  no  logical  force ;  and  they  are  generally  employed 
by  those  who  can  adduce  no  valid  proof  in  support  of 
their  own  opinions,  or  against  their  opponents'. 

A  frequent  instance  of  this  aberrancy  is,  where  it  ap- 
pears that  a  person  will  undergo  serious  loss  or  suffer- 
ing, if  he  disbelieves  a  certain  proposition,  or  adopts  the 
contrary,  and,  therefore,  it  is  inferred  that  it  is  false.  This 
result  has  frequently  been  produced  seemingly,  and  some- 
times really,  by  means  of  imprisonment,  corporal  chas- 
tisement, torture,  loss  of  situation,  or  disapprobation  of 
relatives  and  friends. 

This  aberrancy  is  generally  combined  with  the  preced- 
ing, and  the  combination  has  frequently  imposed  upon 
the  weak-minded,  the  ignorant,  and  the  unprincipled. 
The  advantages  held  out,  on  the  one  hand,  and  the  dis- 
advantages either  threatened  or  actually  inflicted,  on  the 
other,  have  produced,  in  countless  millions,  belief  in  dog- 
mas which  they  might  easily  have  ascertained  to  be  to- 
tally false. 

Fallacies  of  appeals  to  desires  are  greatly  fostered  by 
the  perfect  ease  with  which  they  can  be  used.  To  pro- 
duce facts  or  substantial  arguments  for  or  against  a  prop- 
osition, requires  time  and  labor,  while  it  is  always  very 
easy  to  call  it  by  laudatory  and  pleasing  epithets,  on  the 
one  hand,  or  by  offensive  and  contemptuous  terms,  on 
the  other.  The  former  indirectly  imply  that  it  is  so  well 
established  otherwise,  or  so  perfectly  evident,  that  more 
formal  proof  is  not  required,  or,  conversely,  that  it  is  so 
absurd,  or  so  conclusively  refuted  already,  that  no  elab- 
orate argument  is  now  required  to  disprove  it,  while,  for 
anything  that  appears  to  the  contrary,  the  truth  may  be 
the  very  reverse. 


SEC.  3.]  APPEALS  TO  DESIRES.  323 

These  aberrancies  are  very  apt  to  escape  detection  in 
public  addresses,  because  the  strong  feelings  excited  by 
mutual  sympathy  between  all  present,  both  speaker  and 
hearers,  concentrate  the  attention  on  certain  points,  and 
withdraw  it  from  others,  so  that  the  worthlessness  of  the 
argument  is  overlooked,  although,  in  many  cases,  the 
slightest  analysis  of  it  would  readily  show  that  it  proves 
nothing  at  all. 

Such  fallacies  are  not  only  employed  by  others,  to  mis- 
lead us,  but  we  are  very  liable  to  fall  into  them,  in  our 
own  original  investigations,  since  our  minds  tend  toward 
the  agreeable,  and  against  the  disagreeable,  without  any 
prompting  from  others :  and  indeed  this  native  tendency 
is  requisite,  in  order  to  effect  extraneous  imposition  by 
such  means,  which  are  rarely  effectual,  except  where  we 
are  prepared  to  adopt  them. 

Fallacious  appeals  to  desires  have  been  one  of  the  prin- 
cipal means  of  propagating  and  riveting  error,  in  every 
age  and  country.  They  are  so  numerous  that  it  would 
be  tedious  to  describe  the  various  species  in  detail ;  and 
they  are  all  so  similar  in  their  operation,  and  run  so  much 
into  each  other,  that  such  a  description  would  be  of  little 
use.  The  most  common  and  pernicious  are  those  which 
relate  to  religious,  ethical  and  political  matters ;  and  the 
two  kinds  are  generally  combined,  the  one  side  being  de- 
picted as  very  attractive,  in  order  to  secure  an  easy  be- 
lief, and  the  other  represented  as  quite  repulsive,  in  order 
to  deter  scrutiny. 

These  aberrancies,  however,  are  generally  combined 
with  fallacies  of  comprehension,  testimony,  probability, 
or  appeals  to  authority,  without  which  their  influence 
would  be  comparatively  small,  since  all  know  that  wish- 
es are  not  proofs.  -Sometimes  the  facts  are  first  misrep- 
resented ;  then  a  probability  is  established  on  this  foun- 
dation ;  then  this  is  attempted  to  be  fortified  by  falla- 
cious appeals  to  authority ;  and,  finally,  friendly  and  hos- 
tile passions  are  excited,  to  secure  the  reception  of  the 
error.  In  other  cases,  some  of  these  processes  are  omit- 
ted, or  the  order  of  arrangement  is  reversed,  the  oppos- 
ing views  being  rendered  odious  or  contemptible  in  the 
first  instance,  by  being  grossly  misrepresented. 

As  in  the  case  of  the  simple  aberrancy,  we  may  mis- 
lead ourselves  by  such  combinations,  as  well  as  be  misled 
by  others.  Thus,  we  often  form  a  very  erroneous  opin- 


324  ABERKANCIES.  [CHAP.  XIX. 

ion  regarding  the  character,  condition  and  position  of 
ourselves,  our  friends,  denomination,  or  country.  As  it 
is  pleasant  to  think  well  of  ourselves,  and  unpleasant  to 
think  otherwise,  we  look  at  the  bright  side  of  our  own 
characters  and  at  the  dark  side  of  others,  while  we  exag- 
gerate both ;  and  thus  we  easily  find  probabilities  in  fa- 
vor of  our  own  superior  excellence,  and  improbabilities 
against  our  being  in  the  wrong,  while,  on  the  other  hand, 
we  find,  with  equal  facility,  probabilities  that  others  are 
in  the  wrong,  where  they  differ  from  us,  and  improbabil- 
ities that  they  are  right.  Our  opponents  or  neighbours, 
by  reversing  the  proceeding,  and  looking  at  their  own 
bright  side  and  our  dark  side,  readily  arrive  at  an  oppo- 
site conclusion. 

Such  combinations  have  fostered  selfishness,  pride,  na- 
tional or  sectarian  animosities,  and  an  obstinate  persist- 
ence in  wrong  courses.  Thus,  we  often  flatter  ourselves 
that  we  would  act  much  better  than  others  have  done, 
if  we  were  placed  in  their  circumstances,  because  we  mis- 
take the  nature  of  these,  and  form  erroneous  judgements 
regarding  the  mode  in  which  we  have  acted,  when  placed 
in  similar  circumstances.  If  we  corrected  these  errors, 
we  might  find  that  our  superiority  is  wholly  imaginary. 

Combinations  like  the  preceding  are  sometimes  aided 
by  the  production  or  presence  of  apprehensible  objects. 
The  production  of  a  bloody  knife  has  sometimes  led  to 
the  condemnation  of  the  accused,  where  there  was  no 
satisfactory  proof  of  his  guilt :  and  the  sight  or  smell  of 
liquor  has  often  convinced  a  reformed  drunkard  that  a 
glass  would  do  him  good,  a  few  minutes  after  he  was 
rightly  of  the  contrary  opinion.  Sometimes  the  same  ef- 
fect is  produced  by  broad  allusions,  which  strongly  affect 
the  Memory  or  Imagination  of  the  party  addressed. 

Fallacies  of  this  kind  are  to  be  avoided  by  laying  aside 
desires,  and  addressing  ourselves  attentively  to  the  proofs, 
either  for  or  against  the  conclusion.  We  must  disregard 
both  adulation  and  vituperation  (which  are  generally  used 
only  by  the  advocates  of  error),  and  examine  the  proof 
with  due  care  and  attention.  When  we  have  ascertain- 
ed where  truth  lies,  then,  and  not  before,  it  is  proper  to 
give  way  to  the  feelings  which  it  inspires,  and  to  desig- 
nate doctrines  and  opinions  by  what  we  know  to  be  their 
true  character. 


CHAP.  XX.] 


PARALOGISMS. 


325 


CHAPTER  XX. 


TABLE    OF   FALLACIES. 


I.  PARALOGISMS. 


1.  Paralogisms  of  Intuition 


(  (1.)  Intuitional  assumption. 
\  (2.)  Intuitional  rejection. 

2.  Assuming  what  is  attempted  to  J  (1.)  Assuming  the  question. 

be  proved  \  (2.)  Seasoning  in  a  circle. 

0    r,      7    .          ,.  ~          T  f  (1.)  Miscomprehension. 

3.  Parakgtsrns  of  Compreh^on  j  ^  Incomprehension. 

4.  Paralogisms  of  Signs 


5.  Paralogisms  of  Memory 


6.  Intrinsic  paralogisms  of 
Testimony 


( (1.)  Illusive  sign. 

(  (2.)  Non-interpretation  of  signs. 

f  (1.)  Imaginary  apprehension. 

1  (2.)  False  association. 

j  (3.)  Mistaking  ideas. 

((4.)  Forgetfulness. 
(1.)  Ambiguous  expression. 
(2.)  Overlooking  conditions. 
(3.)  Assuming  conditions. 
(4.)  Obscure  expression. 
(5.)  Wrong  expression. 


Testimony 


(6.)  Falsehood. 
(7.)  Suppressing  truth. 
(8.)  Misrepresenting  comprehensions. 
^(9.)  Misrepresenting  testimony. 
(1.)  Adopting  a  mean. 
(2.)  Counting  witnesses 
7.  Extrinsic  paralogisms  of)  (3.)  Credulity. 
(4.)  Scepticism. 
'5.)  Overlooking  testimony. 
(6.)  Indiscrimination. 
-  (1.)  Misunderstanding  archaisms. 

(2.)  Misinterpreting  technicalities. 

(3.)  Misinterpreting  ambiguities. 

(4.)  Confounding  different  senses. 

(5.)  Overlooking  the  idiom. 

(6.)  Following  etymologies. 

(7.)  Mistaking  the  style. 

(8.)  Misplacing  the  accent. 

(9.)  Misconstruction. 
(10.)  Mistaking  expressions. 
(11.)  Ignorant  interpretation. 
(12.)  Misconception. 
(13.)  Fallacious  implication. 
(14.)  Mistaking  allusions. 
t(15.)  Fallacious  propriety. 


8.  Misinterpreting  Language 


326 


TABLE  OF  FALLACIES.         [CHAP.  XX. 


II.  SOPHISMS. 

1.  Sophisms  of  Confusion 


2.  Sophisms  of  Generaliza- 
tion 


Ifr) 
1(50 

1(6.) 


3.  Sophisms  of  Causation 


4.  Sophisms  of  Proba- 
bility 


(1.)  Sophistical  connection. 
(2.)  Inferring  the  converse. 
(3.)  Altering  propositions. 
(1.)  Sophistical  extension. 
(2.)  Sophistical  inclusion. 
(3.)  Sophistical  contraction. 
Sophistical  exclusion. 
Sophistical  combination. 
Imaginary  universality. 
(1.)  False  cause. 
(2.)  False  effect. 

(3.)  Confounding  cause  and  effect. 
(4.)  Hypothetical  causes. 
(5.)  Mistaking  the  chief  cause. 
(6.)  Mistaking  the  chief  effect. 
(7.)  Mistaking  the  ultimate  cause. 
(8.)  Sophistical  explanation. 
(9.)  Sophistical  induction. 
(10.)  Sophistical  proof. 
(11.)  Sophistical  relation. 
(12.)  Excluding  causes. 
(13.)  Excluding  effects. 
(14.)  Imaginary  effect. 
(15.)  Imaginary  cause. 
r(l.)  Inferring  the  probable,  including 
(a.)  Inferring  hypotheses, 
(6.)  Accumulating  probabilities, 
(c.)  Friends'  opinions, 
(d.)  One-sided  arguments, 
(e.)  Harmonizing  conclusions, 
(f.)  Contingent  connective, 
(<7.)  Incomprehensible  connective, 
(A.)  Inconclusive  investigation, 
(**.)  Sophistical  leap. 
(2.)  Rejecting  the  Improbable,  including 
(a.)  Discordant  opinion, 
(6.)  Overlooking  the  alternative, 
(c.)  Rejecting  theories, 
(</.)  Severing  probabilities, 
(e.)  Enemies'  opinions, 
(y.)  Mortifying  proofs, 
(<7.)  Imaginary  absurdity, 
(A.)  Sophistical  distinction. 
(3.)  Varying  probability,  including 
(a.)  Exaggerating  probability, 
(6.)  Diminishing  probability, 
(c.)  Exaggerating  improbability, 
.(c?,)  Diminishing  improbability. 


CHAP.  XX.] 


ABEEBANCIES. 


327 


III.  ABEBBANCIES. 


1.  Aberrandes  of  Confusion 


2.  Aberrandes  of  Appeals  to 
Authority 


3.  Aberrandes  of  Appeals  to 

Desires 


(1.)  Irrelevant  illustration. 
(2.)  Indefinite  terms. 
(3.)  Irrelevant  analogies. 
(4.)  Deciding  by  character. 
(5.)  Deciding  by  consequences. 
(6.)  Deciding  by  motives. 
(7.)  Deciding  by  appearances. 
(8.)  Irrelevant  induction. 
(9.)  Irrelevant  empiricism. 
(10  )  Irrelevant  objection. 

I  Irrelevant  modification. 

I  Homonymous  expressions. 

I  Verbal  illusion. 

i  Illusive  contradiction. 

I  Confounding  means  and  end. 

Universal  belief. 
2.)  General  belief. 
3.)  Conflicting  opinions. 
4.)  Modern  opinions. 
5.)  Sages'  opinions. 
6.)  Many  arguments. 
(7.)  Pretended  refutation. 
(8.)  Irrelevant  admission. 
|  (1.)  Inferring  the  agreeable. 
(  (2.)  Rejecting  the  disagreeable. 


(11. 

(12. 

(13. 

(14. 

1(15. 

1. 


PART  IV. 


A  SPECIAL  SURVEY  OF  THE  PRINCIPAL  BRANCHES 
OF  KNOWLEDGE. 


CHAPTER  XXL 

CLASSIFICATION  OF  KNOWLEDGE,  ACCOKDING  TO  ITS 
SUBJECTS. 

§  1.  SCIENTIFIC  KNOWLEDGE. — Knowledge  General  or  Particular. — 
Definition  of  Science. — Requisites  to  a  Science. — What  determines 
its  Boundaries. — When  new  Sciences  may  be  formed. — Three 
Classes  of  Sciences. — I.  Subjects  of  Mathematics. — Analysis  and 
Geometry. — Subdivisions  of  each. — Distinction. — II.  Subjects  of 
the  Physical  Sciences. — Their  relation  to  Mathematics. — Their  Di- 
visions.— (1)  Subjects  and  Subdivisions  of  the  Mechanical  Sciences. 
—(2)  Of  tne  Ethereal.— (3)  Of  the  Organical.— (4)  Of  the  Geo- 
graphical Sciences. — III.  Subjects  of  the  Mental  Sciences. — (1) 
Logic.— (2)  Psychology.— (3)  Theology.— (4)  Morality.— (5)  Ju- 
risprudence.— Its  Subdivisions.  — Distinction. 

IN  regard  to  its  nature,  all  knowledge  is  either  gener- 
al or  particular.  Thts  former  comprises — (1)  all  cogni- 
tions which  hold  true  of  a  whole  class,  as  "the  three 
angles  of  a  triangle  are  equal  to  two  right  angles" — "  the 
lion  is  carnivorous" — (2)  those  which  express  a  fact  that 
does  not  materially  vary  for  ages,  as  "  the  Earth  is  about 
96  millions  of  miles  from  the  Sun" — "  the  Nile  flows 
northward  into  the  Mediterranean"— and  (3)  those  which, 
although  they  may  be  essentially  particular,  affect  a 
whole  class,  as  "  Adam  was  the  progenitor  of  all  man- 
kind." The  latter  class  includes — (1)  cognitions  express- 
ing things  which  materially  change,  from  age  to  age,  as 
"  the  population  of  London  is  about  three  millions" — and 
(2)  those  which  express  particular  occurrences,  as  "  Na- 
poleon Bonaparte  died  in  1821."  The  former  class  may 
be  called  scientific,  as  general  cognitions  form  the  main 
and  essential  part  of  every  science,  and  other  facts  are 
employed  only  for  the  sake  of  proof  and  illustration,  or 
to  guide  future  researches  regarding  points  not.  yet  as- 
certained. 

A  science  is,  a  systematic  body  of  general  truths,  re- 
lating to  an  important  subject.  To  render  a  branch  of 
knowledge  a  science,  it  must  possess  the  following  char- 
acteristics. 

1.  Its  propositions  must  be  general:  for  a  series  of 
particular  facts  cannot  evidently  form  a  science. 


332        CLASSIFICATION  OP  KNOWLEDGE.    [CiiAi*.  XXI. 

2.  These  propositions  must  be  so  numerous  as  to  form 
a  body  of  knowledge:   for  a  few  propositions  can  no 
more  form  a  science  than  a  few  sticks  and  stones  can 
form  a  house. 

3.  The  truths  must  be  real  cognitions,  and  not  merely 
believed,  or  fallaciously  argued,  to  be  such.    True  science 
always  consists  of  things  which  are  known  by  immediate 
discernment,  satisfactory  testimony,  or  conclusive  infer- 
ences from  unobjectionable  premises. 

4.  The  truths  must  be  arranged  according  to  some 
principles  of  classification,  so  that  a  person  ignorant  of 
the  subject  can  master  the  whole,  as  it  is  laid  down,  pro- 
vided he  possesses  ordinary  faculties,  and  the  requisite 
preparatory  knowledge.     The  best  materials^  thrown  to- 
gether without  order  or  connection,  are  no  more  a  science 
than  a  heap  of  building  materials  is  a  house. 

5.  The  subject  must  be  important,  either  intrinsically 
or  for  its  bearings  on  other  subjects:  else  it  would  be 
unworthy  of  notice. 

6.  The  cognitions  must  be  distinguishable  from  those 
of  other  sciences :  else  there  would  be  no  occasion  to 
class  them  separately. 

7.  The  truths  must  all  relate  to  one  general  subject,  or 
to  closely  kindred  subjects:    otherwise  the  materials 
would  be  incongruous,  whence  would  result  confusion, 
obscurity,  and  error. 

The  boundaries  of  a  science  are  determined  partly  by 
the  nature  of  the  subject,  and  partly  by  the  objects  which 
it  aims  at  effecting.  It  should  embrace  every  important 
cognition  strictly  belonging  to  its  subject,  and  having  no 
close  relation  to  any  other.  But,  in  some  cases,  cogni- 
tions are  related,  in  nearly  equal  degrees,  to  two  or  three 
sciences :  and  here  we  should  be  guided  by  the  rule  that 
they  ought  to  be  placed  as  the  interests  of  study  require. 
They  should  be  so  arranged  as  to  render  the  attainment 
and  retention  of  knowledge  as  easy  as  possible. 

Inductions  which  do  not  properly  belong  to  any  exist- 
ing science,  and  are  too  few  in  number  to  constitute  a 
separate  one,  should  be  classed  with  that  to  which  they 
bear  the  closest  affinity :  and  when  a  sufficient  number 
of  them  has  been  established,  they  should  be  formed  into 
a  new  science.  So,  when  some  subdivision  of  a  science, 
which  is  of  a  distinct  nature,  has  become  extensive,  it 
should  be  classed  as  a  separate  science.  But  this  course 


&EC.  1.]  SCIENTIFIC  KNOWLEDGE.  333 

is  not  desirable  simply  because  the  subject  may  have  be- 
come very  extensive :  for  it  would  separate  from  each 
other  things  which  are  all  parts  of  one  closely  connected 
whole. 

The  sciences  consist  of  three  classes,  the  mathemat- 
ical^ the  physical  and  the  mental,  the  subjects  and  divis- 
ions of  which  are  as  follows. 

I.  The  mathematical  sciences  treat  of  the  relations  and 
properties  of  abstract  quantity.  As  this  consists  of  num- 
ber and  magnitude,  Mathematics  consist  of  two  corre- 
sponding parts,  Analysis  and  Geometry,  the  former  of 
which  treats  of  numbers,  and  the  latter,  of  magnitudes. 

Analysis  employs  various  symbols  or  signs,  some  of 
which  express  quantities — as  1,  2,  3,  a,  b,  x,  y,  z — and  oth- 
ers express  the  relations  of  quantities,  or  the  operations 
to  be  performed  on  them — as  -}-,  — ,  x,  — ,  <,  ^.  It  is 
of  two  kinds,  Special,  where  the  symbols  have  all  a  spe- 
cial signification, — as  1,  2,  3 — and  General,  where  these 
have  a  general  signification- — as  a,  b,  x,  y.  The  former 
is  commonly  termed  Arithmetic,  and  the  latter,  Algebra. 

Algebra  is  subdivided  into  the  Elementary  and  the 
Higher.  The  former  employs  only  constants,  or  symbols 
and  functions  which  have  but  one  value  throughout  the 
processes  or  operations  in  which  they  appear :  the  latter 
employs  variables,  or  symbols  and  functions  which  vary 
in  value  in  the  same  expression  or  operation,  while  the 
different  values  are  frequently  indefinitely,  or,  as  it  is  oft- 
en expressed,  infinitely  small. 

Geometry  treats  of  the  four  kinds  of  magnitude,  lines, 
angles,  surfaces  and  solids,  the  mathematical  signification 
of  which  differs  from  the  physical.  The  former  includes 
only  the  various  forms  of  pure  extension,  and  excludes 
all  conception  of  material  substances.  Thus,  a  physical 
line  has  always  some  breadth  and  thickness,  but  a  math- 
ematical line  has  none.  Geometrical  magnitudes  are  rep- 
resented to  our  apprehension,  however,  by  physical  sym- 
bols, which  greatly  assist  us  in  studying  the  science. 

Geometry  consists  of  two  parts — Synthetical  or  Pure, 
which  treats  of  its  objects  directly,  without  the  aid  of 
Analysis — and  Analytical  or  Algebraic,  in  which  the 
propositions  are  investigated  by  means  of  Analysis. 
The  latter  represents  the  magnitudes  by  numerical  quan- 
tities, while  the  former  represents  them  directly. 

Analytical  Geometry  is  subdivided  into  Determinate, 


334        CLASSIFICATION  or  KNOWLEDGE.    [CHAP.  XXI. 

which  discusses  problems  that  admit  only  of  a  limited 
number  of  solutions,  and  Indeterminate,  which  treats  of 
problems  that  admit  of  an  indefinite  number  of  solutions. 
In  the  former,  the  symbols  which  represent  the  unknown 
quantities  have  only  one  or  a  few  values,  while,  in  the 
latter,  they  vary  indefinitely,  and  consequently  it  enables 
us  to  discuss  the  general  properties  of  geometrical  quan- 
tities. 

II.  The  physical  sciences  treat  of  physical  or  material 
nature,  including  whatever  is  directly  cognizable  by  our 
senses.  They  sometimes  employ  mathematical  proposi- 
tions very  extensively,  in  deducing  inferences  from  fun- 
damental principles.  Yet  they  always  differ  essentially 
from  Mathematics,  in  treating  of  material,  beings,  and  not 
of  abstract  quantity.  They  may  be  divided  into  the  three 
following  classes.  (1)  The  inorganical,  which  treat  of 
inorganic  nature  exclusively.  (2)  The  organical,  which 
treat  only  of  organic  nature,  or  of  plants  and  animals. 
(3)  The  geographical^  which  treat  of  both.  The  first 
class  comprises  the  mechanical,  which  treat  of  pondera- 
ble matter,  and  the  ethereal,  which  treat  of  imponderable 
matter.  Ponderable  matter  is  that  which  gravitates,  or 
possesses  weight:  imponderable  matter  is  that  which 
does  not  gravitate,  or  possesses  no  weight. 

1.  The  mechanical  sciences  treat  chiefly  of  the  me- 
chanical properties  of  matter,  the  forces  dependent  on 
these  properties,  and  the  motions  or  equilibrium  which 
they  produce.  Mechanical  properties  are  those  which 
are  directly  cognizable  by  our  senses,  and  at  the  same 
time  tend  to  produce  motion  or  rest  in  the  bodies  in 
which  they  inhere,  such  as  weight,  rigidity,  elasticity, 
fluidity,  roughness  and  smoothness.  The  following  are 
the  sciences  belonging  to  this  subdivision. 

(a.)  Mechanic,  which  treats  of  solid  bodies,  or  those 
whose  parts  firmly  cohere.  It  consists  of  three  parts — 
Static,  which  treats  of  solid  bodies  in  a  state  of  equilib- 
rium— Dynamic,  which  treats  of  the  motions  of  such 
bodies,  and  the  forces  by  which  they  are  produced — and 
Mechanism,  which  treats  of  the  mechanical  properties 
of  solids,  the  communication  and  distribution  of  motion, 
and  the  principles  of  machinery  and  engineering,  irre- 
spectively of  the  moving  forces. (19) 

(b.)  Hydric,  which  treats  of  liquids,  or  those  bodies 
whose  parts  do  not  cohere,  or  only  very  slightly,  but  yet 


SEC.  1.]  SCIENTIFIC  KNOWLEDGE.  335 

are  not  repelled,  and  move  with  little  mutual  friction. 
It  consists  of  Sydrostatic,  which  treats  of  liquids  in  a 
state  of  equilibrium — Hydrodynamic,  which  treats  of 
liquids  in  motion — Ilydromechanism,  which  discusses 
the  mechanical  properties  of  liquids,  the  means  of  rais- 
ing, conducting  and  confining  them,  and  the  principles 
and  construction  of  water  works. 

(c.)  Pneumatic,  which  treats  of  gaseous  bodies,  or 
those  whose  parts,  instead  of  cohering,  are  mutually  re- 
pelled from  each  other. 

(d.)  Acoustic,  the  science  of  sound  and  hearing.  As 
air  is  the  ordinary  medium  of  sound,  this  science  is  close- 
ly connected  with  the  preceding. 

(e.)  Astronomy,  the  science  of  the  heavenly  bodies. 
It  is  subdivided  into  Practical,  which  treats  of  the  use 
of  astronomical  instruments,  and  the  apparent  magni- 
tudes, positions,  aspects  and  motions  of  the  heavenly 
bodies  —  Descriptive,  which  discusses  their  real  condi- 
tions, motions,  sizes,  and  distances : — and  Dynamical, 
which  investigates  the  nature  and  effects  of  the  forces 
that  control  their  motions,  and  thence  deduces  their  fu- 
ture positions,  so  that  these  can  be  accurately  laid  down 
in  tables.  Descriptive  Astronomy  is  subdivided  into 
Heliography,  Selenography,  Planetography,  Cometogra- 
pliy  and  Asterography  or  Sidereal  Astronomy,  which 
treat  respectively  of  the  Sun,  Moon,  planets,  comets,  and 
fixed  stars. 

2.  The  ethereal  sciences  treat  of  the  properties  of  the 
imponderable  agents,  all  of  whose  phenomena  appear  to 
depend  on  different  kinds  of  undulations,  or  small  waves, 
propagated  through  an  invisible  and  very  subtile  medium 
termed  ether,  whence  I  have  designated  them  as  above. 
They  consist  of  the  following  sciences. 

(a.)  Optic,  the  science  of  light  and  vision.  It  is  sub- 
divided into  Physical,  which  treats  of  the  nature  of  light 
and  vision, — and  Mathematical,  which  discusses  the  pro- 
duction of  images,  and  the  consequences  deducible  from 
the  general  laws  of  reflection,  refraction  and  polarization. 

(b.)  Thermotic,  the  science  of  heat.  Like  the  preced- 
ing, it  may  be  subdivided  into  the  Physical  and  the 
Mathematical. 

(c.)  Electric,  the  science  of  electricity.  It  may  be  sub- 
divided into — Electrostatic,  which  treats  of  electricity  in 
equilibrium — Electrodynamic,  which  treats  of  electricity 


336         CLASSIFICATION  OF  KNOWLEDGE.    [CHAP.  XXI. 

in  motion — and  Electromechanism,  which  investigates 
the  nature  and  force  of  the  electric  fluid,  and  the  pecul- 
iar principles  of  machinery  worked  by  electric  forces. 
Electrodynamic  includes  Galvanism,  which  treats  of  gal- 
vanic or  ordinary  electric  currents,  and  Magnetism,  which 
treats  of  magnetic  electricity 

3.  The  organical  sciences  are  the  following . 

(a.)  Botany,  the  science  of  plants,  or  inanimate  organ- 
isms. It  consists  oiPhytology,  which  treats  of  the  struc- 
ture and  development  of  plants  in  general — and  Descrip- 
tive Botany,  which  describes  the  peculiar  properties  of 
the  various  subdivisions,  classified  according  to  their 
structure. 

(b.)  Zoology,  or  Natural  History,  which  describes  the 
various  kinds  of  animals.  It  consists  of  as  many  subdi- 
visions as  there  are  classes  of  animals,  such  as  Mammal- 
ogy (history  of  mammals)  —  Ornithology  (history  of 
birds) — Herpetology  (history  of  reptiles) — Ichthyology 
(history  of  fishes) — Malacology  (history  of  mollusks) — 
Entomology  (history  of  insects) — ^lelminthology  (his- 
tory of  worms)  &c. 

(c.)  Anatomy,  which  describes  methodically  the  vari- 
ous organs  of  animals,  and  the  specific  functions  of  each. 
It  is  subdivided  into  General,  which  treats  of  the  organs 
of  animals  generally — Comparative,  which  discusses  the 
analogous  or  corresponding  parts  of  the  various  classes 
— and  Human,  which  gives  a  description  of  all  the  organs 
of  the  human  frame. 

(d.)  Physiology,  the  science  of  the  phenomena  of  ani- 
mated or  living  beings.  Like  Anatomy,  it  is  subdivided 
into  General,  which  discusses  the  structure  and  functions 
of  animal  organisms  generally —  Comparative,  which 
treats  of  such  as  are  peculiar  to  the  various  classes  of 
animals — and  Human  which  is  confined  to  man  alone, 
and  includes  Hygiene,  the  doctrine  of  the  laws  of  health, 
and  Ethnology,  which  investigates  the  origin  and  physic- 
al characteristics  of  the  various  races  of  men. 

(e.)  Pathology,  which  treats  of  the  phenomena  and 
laws  of  morbific  and  curative  agencies.  It  comprises 
Nosology,  which  treats  of  the  general  nature  and  phases 
and  the  classification  of  diseases — ^Etiology,  the  doctrine 
of  the  causes  of  diseases,  including  Toxicology,  which 
treats  of  the  action  of  poisons — Symptomatology  or  Se- 
meiology,  including  Anatomical  Pathology,  which  treats 


SEC.  l.'J  SCIENTIFIC  KNOWLEDGE.  337 

of  the  characteristic  symptoms  of  diseases,  and  of  the  in- 
dications of  their  future  course  and  results — and  Thera- 
peutic^ which  discusses  the  remedies  and  proper  treat- 
ment of  diseases,  including  the  nature,  operations  and  re- 
sults of  medicines  and  other  curative  agencies.  These 
branches  are  properly  blended  Avith  each  other,  in  many 
instances ;  and  they  are  all  closely  connected  with  the 
arts  of  Surgery  and  Medicine. 

4.  The  geographical  sciences  treat  of  the  Earth,  and 
such  of  its  natural  phenomena  as  do  not  belong  to  any 
of  the  preceding  sciences.  They  consist  of  Geography, 
Chemistry,  Mineralogy  and  Geology. 

(a.)  Geography  gives  a  general  description  of  the 
Earth,  and  the  scientific  phenomena  presented  by  its  sev- 
eral parts,  including  a  general  account  of  their  animal 
and  vegetable  productions.  It  may  be  subdivided  into 
General  or  Mathematical,  which  treats  of  the  form,  size, 
motions  and  density  of  the  Earth,  and  the  means  of  de- 
termining the  positions  and  distances  of  places  on  its 
surface,  and*delineating  them  on  a  sphere  or  plane — 
Geognosy,  which  discusses  the  natural  phenomena  pre- 
sented by  the  land  —  Hydrology,  which  treats  of  the 
oceans,  seas,  and  streams — and  Meteorology,  which  gives 
an  account  of  the  general  properties  of  the  atmosphere 
and  its  phenomena,  including  aerial,  aqueous,  and  lumin- 
ous meteors,  and  the  extensive  and  interesting  subjects 
of  winds  and  climates. 

(b.)  Chemistry  investigates  the  nature  of  the  simple 
substances  of  which  all  ponderable  objects  are  com- 
posed, and  describes  both  these  elements  and  the  com- 
pounds formed  from  them,  including  the  laws  of  their 
composition  and  decomposition.  It  is  subdivided  into 
Inorganic,  which  treats  of  the  simple  elements,  and  such 
compounds  as  are  found  in  inorganic  substances — and 
Organic,  which  treats  of  such  compounds  as  occur  only 
in  organic  bodies. 

(c.)  Geology  treats  of  the  rocks  or  mineral  masses  that 
compose  the  Earth,  and  of  the  organic  remains  contained 
in  them.  It  may  be  subdivided  into  Petrology,  which 
describes  the  various  rocks,  and  investigates  their  origin 
—  and  Palaeontology,  which  describes  the  organic  re- 
mains found  in  the  rocks,  and  investigates  the  structure 
of  the  original  organisms,  and  the  circumstances  in  which 
they  existed. 

P 


338         CLASSIFICATION  OF  KNOWLEDGE.    [CHAP.  XXL 

(cl.)  Mineralogy  discusses  the  chemical  composition, 
the  mechanical  properties,  the  crystaliuc  form,  and  the 
situation  of  solid  minerals  and  crystals.  It  may  be  sub- 
divided into  Mineralography,  which  treats  of  the  chem- 
ical composition  and  other  properties  of  minerals,  apart 
from  their  crystaline  form — and  Crystalograpliy,  which 
treats  of  the  crystaline  form  of  minerals. 

III.  The  mental  sciences  are  those  which  chiefly  regard 
mind,  or  things  imperceptible  to  the  senses,  and  treat  of 
other  matters  only  as  connected  with  their  main  subjects. 
They  are  included  in  the  following  enumeration. 

1.  Logic,  which  has  been  already  defined. 

2.  Psychology,jhe,  science  of  the  human  mind.    It  un- 
folds the  nature  of  the  mental  faculties,  both  intellectual 
and  emotional,  and  discusses  everything  regarding  them 
which  does  not  fall  within  the  province  of  Logic. 

3.  Theology  treats  of  the  existence  and  attributes  of 
the  Deity,  and  the  relation  in  which  man  stands  to  him, 
as  an  intelligent  and  immortal  being.     It  consists  of 
Natural  Theology,  which  investigates  the«evidence  re- 
garding God  and  the  future  destination  of  man  afforded 
by  the  works  of  nature — and  Biblical  Theology,  which 
pursues  the  same  subjects,  under  the  additional  light  de- 
rived from  the  Sacred  Scriptures. 

4.  Morality  or  Ethic  inquires  into  the   nature    and 
sanctions  of  duty  in  general,  and  investigates  the  princi- 
ples which  determine  particular  duties. 

5.  Jurisprudence  is  the  science  of  juridical  law.     It 
consists  of  two  parts — Public  Jurisprudence,  which  in- 
vestigates the  foundation  and  sanctions  of  government, 
and  discusses  the  structure  and  peculiarities  of  its  vari- 
ous leading  forms  —  and  Private  Jurisprudence,  which 
investigates  the  subjects  and  principles  of  private  law. 
Each  part  may  be  subdivided  into  National  and  Interna- 
tional.    National  Public  Jurisprudence  treats  of  the  in- 
ternal government  of  a  nation.     It  exhibits  the  functions 
of  the  various  departments  of  government,  and  the  prop- 
er modes  of  conducting  public  affairs.     Internationa* 
Public  Jurisprudence  discusses  the  intercourse  between 
different  states,  or  between  individuals  and  foreign  gov- 
ernments.    National  Private  Jurisprudence  unfolds  the 
juridical  rights  and  duties  of  private  members  of  a  state., 
in  relation  to  each  other.     International  Private  Juris- 
prudence shows  the  mutual  rights  and  obligations  of 


SEC.  1.]  MTXED  KNOWLEDGE.  339 

private  subjects  of  different  governments,  in  their  inter- 
course with  one  another. 

The  science  of  jurisprudence  is  to  be  distinguished 
from  an  exposition  of  the  laws  of  a  particular  state,  two 
things  which  differ  as  much  as  Hygiene  and  an  account 
of  the  mode  of  living  of  some  particular  community. 
The  former  is  as  unchangeable  as  the  nature  of  man  :  the 
latter  changes  from  age  to  age,  or  even  from  year  to 
year,  so  that  it  is  not  a  science  at  all,  but  merely  an  art, 
to  enable  a  man  to  expound  or  administer  the  existing 
laws  of  the  state. 

§  2.  MIXED  KNOWLEDGE. — What  is  meant  by  this  term. — Subdivi- 
sions.— Art. — (1)  Philology. — Dead  and  Living  Languages. — (2) 
Ethnography. — Archaeology. — (3)  Technology. — Three  principal 
kinds  of  Arts. — Distinctions. 

By  mixed  Jcnoicledge  are  understood  those  branches 
of  which  general  propositions  and  particular  statements 
form  essential  parts.  It  may  be  subdivided  into  Philol- 
ogy, which  treats  of  words  or  language — Ethnography, 
which  describes  states,  communities,  and  towns — and 
Tedinograpliy,  which  discusses  the  modes  of  operating 
in  the  various  arts.  An  art  is,  a  body  of  rules  for  effect- 
ing some  known  end,  writh  such  directions  and  explana- 
tions as  may  be  requisite  for  their  due  application. 

1.  Philology  may  be  divided  into  three  main  parts: 
(1)  Special  Philology  or  Grammar  unfolds  the  elements 
and  structure  of  some  particular  language,  and  lays  down 
rules  for  obtaining  an  adequate  knowledge  and  command 
of  it.     It  consists  of  two  parts — (a)  that  which  treats  of 
dead  languages,  or  those  which  have  ceased  to  be  spoken 
by  any  community — and  (b)  that  which  treats  of  living 
languages,  or  such  as  are  used  by  communities,  as  their 
ordinary  speech.     (2)  Comparative  Philology  treats  of 
the  agreements  and  diversities  exhibited  by  one  or  more 
groups   of  kindred  languages.     (3)   General  Philology 
discusses  the  structure  of  language  in  general,  and  the 
conditions  requisite  in  order  to  its  fulfilling  the  objects 
of  language. 

2,  Ethnography  comprises  descriptions  of  the  follow- 
ing subjects.     (1)  The  political  divisions  and  institutions 
of  the  various  states,  including  the  nature  of  their  gov- 
ernments and  laws.    (2)  Their  races  of  men,  populations, 
and  resources.     (3)  Their  religious  tenets,  and  moral 


340          CLASSIFICATION  OF  KNOWLEDGE.  [CHAP.  XXI. 

condition.  (4)  Their  social  institutions,  manners,  and 
customs.  (5)  Their  language,  science,  and  literature. 
(6)  Their  arts,  manufactures,  and  commerce.  (7)  Their 
cities,  towns,  and  remarkable  edifices. (20) 

The  condition  of  all  these  subjects  generally  varies, 
more  or  less,  from  age  to  age ;  and  the  description  may 
apply  either  to  the  present  or  the  past,  in  which  case  it 
is  frequently  termed  Archaeology  or  Antiquities. 

3.  Technology  comprises  the  three  following  classes 
of  arts. 

(1)  The  mechanical,  which  aim  at  effecting  some  change 
in  material  elements,  to  minister  to  the  necessities  or  the 
comfort  and  convenience  of  mankind,  such  as  Tillage  (in- 
cluding Agriculture,  Horticulture,  and  Arboricidture), 
Pasturage,  or  the  art  of  managing  flocks  and  herds,  Met- 
allurgy, Spinning,  Weaving,  and  Architecture. 

(2)  The  intellectual,  or  those  whose  immediate  object 
is,  to  solve  problems,  although  some  material  change  is 
often  sought,  as  a  further  end.     Such  are  Government, 
the  art  of  executing  the  public  laws — Statesmanship, 
the  art  of  obviating  difficulties  in  the  administration  of 
these  laws,  and  improving  them  where  bad  or  defective 
— Diplomacy,  the  art  of  conducting  negotiations  with 
foreign  governments — Law,  the  art  of  expounding  and 
administering  the  private  laws — Rhetoric,  the  art  of  per- 
suasion and  the  communication  of  truth — Education,  the 
art  of  training  and  instructing  the  young — and  Naviga- 
tion, the  art  of  directing  the  course  and  finding  the  posi- 
tion of  a  ship  at  sea. 

(3)  The  emotional,  or  such  as  are  designed  chiefly  to 
excite  agreeable  feelings.     Of  this  kind  are  Poetry,  Mu- 
sic, and  the  imitative  arts,  including  Painting,  Photog- 
raphy, and   Sculpture.     They  differ  from  Rhetoric   in 
making  pleasing  feelings  their  chief  end,  whereas  the  for- 
mer uses  these  only  as  means  towards  its  main  object 
of  producing  conviction  and  action.     They  also  differ 
from  the  sciences  in  making  instruction  and  mental  dis- 
cipline only  secondary  ends,  while  the  sciences  reverse 
the  case,  and  make  these  their  chief  objects. 

§  3.  PARTICULAR  KNOWLEDGE. — Its  most  important  Subjects. — (1) 
History. — Its  chief  divisions. — (2)  Chronology. — (3)  Biography. — 
Its  principal  Divisions. 

Exclusive  of  those  which  relate  to  science  or  art,  par- 


SEC.  4.]  PARTICULAR  KNOWLEDGE.  341 

ticular  facts  of  general  interest  or  importance,  belong 
chiefly  to  History,  Chronology,  or  Biography. 

1 .  History  is,  a  narrative  or  continuous  account  of  past 
events,  regarding  communities  or  classes  of  mankind,  in- 
cluding a  view  of  their  more  immediate  causes  and  ef- 
fects.    It  consists  of  a  great  variety  of  parts,  according 
to  the  country,  time,  or  subjects  embraced.     That  of  the 
same  age  and  country  comprises  the  following  (1)  Eccle- 
siastical, or  that  of  religious  affairs  and  morals.    (2)  That 
of  science,  literature,  and  language.     (3)  That  of  legisla- 
tion and  law.     (4)  That  of  political  and  military  transac- 
tions.    (5)  That  of  domestic  life  and  manners.     (6)  That 
of  the  arts,  manufactures,  and  commerce. 

2.  Chronology  is,  an  investigation  and  exposition  of 
the  dates  of  historical  events,  for  the  purpose  of  their 
being  duly  arranged  in  the  order  of  their  occurrence. 

3.  Biography  is,  an  account  of  the  lives  and  characters 
of  remarkable  persons,  the  circumstances  which  directly 
influenced  them,  and  the  effects  which  they  immediately 
produced.     It  bears  much  the  same  relation  to  individ- 
uals that  History  does  to  states  or  classes  of  men.     It 
comprises  the  following  divisions.     (1)  Religious  and 
moral,  containing  the  lives  of  persons  distinguished  for 
their  piety  and  benevolence.     (2)  Scientific  and  literary, 
including  the  lives  of  men  of  science,  scholars,  and  au- 
thors.   (3)  Professional  and  Artistic,  containing  the  lives 
of  persons  distinguished  for  great  improvements  or  skill 
in  the  professions  and  arts.     (4)  Political  and  military, 
embracing  the  lives  of  celebrated  rulers,  statesmen,  and 
warriors.     (5)  Miscellaneous,  including  the  lives  of  per- 
sons distinguished  in  several  respects,  or  for  something 
peculiar  or  remarkable  connected  with  them,  exclusive 
of  any  personal  excellence  or  achievement.     These  vari- 
ous parts  may  be  subdivided  according  to  time  and  place. 

§  4.  TABLE  OP  THE  PRINCIPAL  BRANCHES  OF  KNOWLEDGE. 
I.  THE  SCIENCES. 
1.  Mathematics. 

{Arithmetic. 
A1  (Elementary 

Algebra  | 

(  Synthetical. 
(2.)  Geometry 

( Analytical 


342          CLASSIFICATION  OF  KNOWLEDGE.  [CHAP.  XXI. 

2.  The  Physical  Sciences. 

(  Static, 
(a.)  Mechanic    <  Dynamic. 

(  Mechanism. 

(  Hydrostatic. 

(6.)  Hydric         <  Hydrodynamic. 
(1.)  Mechanicals  ( Hydromechanism. 

(c.)  Pneumatic. 
(d.)  Acoustic. 

{Practical. 
Descriptive. 
Dynamical. 

(a.)  Optic. 
(6.)  Thermotic. 

fc>  >  I?  u        i       )  I  Electrostatic. 

(2.;  ^th<  eal      <         _       _         I  Electrodynamic,  including 

j  Galvanism  and  Magnetism, 
f  Electromechanism. 


(c.)  Electric 


(3.)  Organical 


(a.)  Botany 


(  Phytology. 

(  Descriptive  Botany. 

{Mammalogy. 
Ornithology. 
Herpetology. 
Ichthyology. 
Malacology. 
Entomology. 
Helminthology,  &c. 
(  General. 

(c.)  Anatomy.    <  Comparative. 
(  Human. 
i  General. 


(4.)  Geographical 


3.  Mental  Sciences. 
(1.)  Logic.  - 


Hygiene  and  Ethnology. 
(  Nosology.  [cology. 

j  ^Etiology,   including  Toxi- 
<  Symptomatology,  inclu 

Anatomical  Pathology. 
;  Therapeutic. 

General. 


j 
(e.)  Pathology  <  Symptomatology,  including 


—  -» 


Meteorology. 


SEC.  4.]  TABLE  OF  KNOWLEDGE.  343 

(2.)  Psychology. 

(30  Theology'^™!; 

(4.)  Morality  or  Ethical  Science. 

I  (a  \  Public   1  National. 
(5.)  Jurisprudence     (  I  International. 

|(6.)  Private  {fn^:ona, 

II.  MIXED  KNOWLEDGE. 

1.  Philology. 

n  ~\  Snprial  I  Dead  LanSuages- 
al  }  Living  Languages. 

(2.)  Comparative. 
(3.)  General. 

2.  Ethnography. 

(1.)  Political  Divisions  and  Institutions. 

(2.)  Races  of  Men,  Population,  and  Resources. 

(3.)  Religion  and  Morals. 

(4.)  Social  Institutions,  Manners,  and  Customs. 

(5.)  Language,  Science,  and  Literature. 

(6.)  Arts,  Manufactures,  and  Commerce. 

(7.)  Cities,  Towns,  and  Remarkable  Edifices. 

3.  Technology. 

(1.)  Mechanical  Arts. 
(2.)  Intellectual  Arts. 
(3.)  Emotional  Arts. 

III.  PARTICULAR  KNOWLEDGE. 

1.  History. 

(1.)  Ecclesiastical. 

(2.)  Scientific  and  Literary. 

(3.)  Legal. 

(4.)  Political  and  Military. 

(5.)  Social. 

(6.)  Artistic  and  Commercial. 

2.  Chronology. 

3.  Biography. 

(1.)  Religious  and  Moral. 
(2. )  Scientific  and  Literary. 
(3.)  Professional  and  Artistic. 
(4.)  Political  and  Military. 
(5.)  Miscellaneous. 


344  MATHEMATICS.  [CHAP.  XXIL 


CHAPTER  XXIL 

OF     MATHEMATICS. 

§  1.  PECULIARITIES  OF  MATHEMATICS.  —  General  Nature  and  Sub- 
jects of  Mathematics. — Errors  regarding  them. — Distinction  be- 
tween a  Theorem  and  a  Problem. — Mathematical  Definitions. — 
How  the  essential  nature  of  Mathematical  Quantities  is  known. — 
Axioms. — Mathematical  Reasoning. — Characteristic  of  Analysis. 
— Its  relation  to  Geometry. — General  Principle  which  connects 
the  two. — Unit  of  Measure. 

MATHEMATICS  adopt,  as  primary  premises,  the  exist- 
ence and  some  self-evident  properties  of  certain  abstract 
quantities,  the  essential  peculiarities  of  which  are  either 
accurately  defined  or  known  by  Intuition ;  and  they  de- 
duce from  these  premises,  by  means  of  ordinary  reason- 
ing, and  independently  of  experience,  a  long  series  of 
connected  inferences  and  conclusions,  which  express  the 
properties  and  relations  of  those  quantities,  and  consti- 
tute the  body  of  these  sciences.  Hence  Mathematics  are 
based,  in  no  degree,  on  experience  or  testimony,  and  they 
are  totally  independent  of  every  other  department  of 
knowledge,  while  their  truths  are  all  necessary,  and  never 
contingent,  so  that  they  are  universally  true,  independ- 
ently of  time  and  place. 

Some  have  considered  mathematical  truths  only  hypo- 
thetical, upon  the  alleged  ground  that  mathematical  quan- 
tities do  not  exist  in  nature.  But  the  existence  of  such 
quantities  is  as  self-evident  as  that  of  time  and  space. 
Although  the  most  slender  wire  has  some  breadth,  yet, 
there  is  a  mathematical  line  running  through  it  which 
has  none.  Such  quantities  not  only  exist,  but  they  are 
wholly  independent  of  the  physical  objects  which  may 
have  suggested  to  us  their  nature,  or  in  connection  with 
which  we  frequently  consider  them. 

Another  error  regarding  Mathematics  is,  that  they  are 
based  chiefly  on  observation.  It  is  easily  seen  that  they 
are  quite  independent  of  observation,  which  shows  only 
what  is,  at  a  particular  time  and  place,  while  these  sci- 
ences are  confined  to  propositions  which  are  necessarily 
true,  in  all  times  and  places. 


SEC.  1.]  THEIR  PECULIARITIES.  345 

The  distinction  between  a  theorem,  or  something  'laid 
down  to  be  proved,  and  a  problem,  or  something  proposed 
to  be  done,  is  not  fundamental,  but  only  formal,  since  the 
thing  to  be  done  is  effected  by  means  of  some  theorem, 
which  is  proved,  though  not  formally  stated.  The  prob- 
lems are,  in  fact,  corollaries,  or  easy  inferences  from  the 
theorems ;  and  every  problem  might  be  stated  as  a  the- 
orem, and  the  mode  of  forming  the  figure,  or  calculating 
the  quantity,  appended  as  a  corollary. 

Mathematical  definitions  are  generally  suggested  by 
obvious  properties  of  material  objects  with  which  we  are 
familiar:  but  we  abstract  from  the  definition  something 
which  is  present  in  the  object ;  and  we  frame  it  so  that 
we  can  reason  from  it  with  rigid  accuracy,  irrespectively 
either  of  the  additional  peculiarities  or  the  variations 
found  in  physical  objects.  Such  definitions  are  not  only 
very  precise  and  intelligible,  but  they  give  us  a  knowl- 
edge of  the  essential  peculiarity  of  the  thing  defined. 

The  essential  nature  of  the  thing  defined  is  known  in- 
tuitively, by  simply  considering  the  definition,  although 
physical  symbols  facilitate  an  understanding  of  the  defi- 
nition. Indeed,  in  various  instances,  we  know  the  nature 
of  the  quantity  without  any  definition.  Thus  we  know 
the  nature  of  a  straight  line  and  a  plane  rectilineal  angle, 
as  soon  as  we  see  two  straight  lines  crossing  each  other, 
while  all  the  definitions  of  them  that  can  be  given  are 
only  verbal,  and  help  us  to  understand  the  nature  of  the 
quantities  as  little  as  definitions  of  red  or  blue. 

Mathematical  reasoning  does  not  differ  from  any  other 
reasoning.  The  intuitive  principles  employed  are  termed 
axioms  :  but  they  differ,  in  no  respect,  from  other  prin- 
ciples of  reasoning,  and  they  are  employed  in  the  same 
way.  Several  of  them,  indeed,  are  formally  stated ;  but 
this  makes  no  difference  in  the  reasoning,  which  is  inde- 
pendent of  any  such  statements.  Not  only  are  these  not 
made,  in  many  treatises  on  Mathematics ;  but  those  which 
do  give  them,  employ  many  which  they  do  not  state  or 
formally  refer  to. 

The  characteristic  of  Analysis  is,  that  it  immediately 
regards  number  only ;  and  it  indicates  magnitudes  solely 
because  these  are  expressible  by  numbers.  The  processes 
employed  in  Analytical  Geometry  are  not  more  applica- 
ble to  Geometry  than  to  other  subjects  that  fulfil  the  same 
numerical  conditions.  Geometrical  properties  are  ascer- 

P2 


346  MATHEMATICS.  [CHAP.  XXII. 

tained  by  means  of  Analysis,  because  they  bear  certain 
obvious  or  ascertainable  relations  to  the  numbers  express- 
ing the  magnitudes  of  the  various  parts  of  its  figures. 
Synthesis  is  connected  with  Analysis  by  the  general  prin- 
ciple that  the  properties  and  relations  of  magnitudes  cor- 
respond to  those  of  the  symbols  which  rightly  represent 
them.  Thus,  if  one  line  is  three  inches  long,  and  another 
five,  the  lines  are  to  each  other  in  that  ratio. 

The  letters  employed  in  Analysis  do  not  properly  rep- 
resent quantity,  but  only  the  numbers  that  are  assumed 
to  measure  them.  A  unit  of  measure  is  always  assumed, 
in  Analytical  Geometry :  otherwise  Algebra  would  be  as 
useless  as  it  is  in  ordinary  arithmetical  calculation.  But 
no  unit  need  be  expressed,  because  the  results  are  unaf- 
fected by  the  particular  one  which  is  supposed  to  be  em- 
ployed. 

§  2.  USES  OF  MATHEMATICS. — (1)  They  form  an  excellent  Mental 
Discipline. — (2)  They  are  extensively  employed,  in  many  Arts  and 
Sciences. — Applications  of  the  various  Tarts. 

1.  Mathematics  are  an  excellent  means  of  initiating  the 
mind  into  habits  of  close  and  continuous  reasoning.    The 
study  is  comparatively  easy ;  and  it  is,  in  a  great  meas- 
ure, free  from  the  prejudices  and  illusions  which  accom- 
pany several  other  branches  of  knowledge,  while  these 
sciences  abound  with  long  and  rigorous  chains  of  reason- 
ing, which  must  be  attentively  examined,  before  any  real 
progress  can  be  made  in  the  study. 

2.  These  sciences  are  of  great  utility  on  account  of 
their  numerous  applications  in  the  arts  and  sciences, 
many  of  which  are  wholly  dependent  on  them ;  and  their 
assistance  is  more  or  less  requisite,  in  order  to  obtain  an 
extensive  and  accurate  knowledge  of  most  of  the  phys- 
ical sciences.     Their  applications  in  the  arts  are  so  fre- 
quent and  familiar  that  it  can  hardly  escape  the  knowl- 
edge of  anybody ;  and,  even  in  History,  the  dates  of  many 
occurrences  have  been  settled,  and  some  anachronisms 
detected,  by  means  of  these  sciences,  where  the  problems 
could  be  solved  in  no  other  way. 

Ordinary  numerical  problems  can  be  solved  by  means 
of  Arithmetic :  but  those  which  require  us  to  operate 
with  a  quantity,  before  its  value  is  determined,  or  to  ex- 
press general  properties,  can  be  solved  only  by  means  of 
the  concise  and  general  symbols  of  Algebra.  For  we 


SEC.  3.]  STUDY  OF  MATHEMATICS.  347 

cannot,  by  any  other  means,  either  remember  the  various 
parts  of  the  process,  so  as  to  perform  the  requisite  oper- 
ations aright,  or  discuss  satisfactorily  the  relations  of  the 
several  quantities. 

All  problems  relating  to  magnitudes  require  the  aid 
of  Geometry,  although  that  of  Analysis  also  is  generally 
more  or  less  requisite.  (21) 

§  3.  STUDY  OP  MATHEMATICS. — Most  important  Points,  at  the  Com- 
mencement.— Principal  things  to  be  guarded  against. — Superior 
Methods. — Aids  of  Generalization. — Selection  of  Propositions. — 
Working  Problems. — Positive  and  Negative  Results. — Signification 
of  isolated  Negative  Quantities. — Source  of  Difficulty. — Extended 
Significations. — Distinction. — Imaginary  Quantities. — Advantages 
of  Analytical  Geometry. — Uses  of  the  Synthetical. — Means  of  ex- 
tending and  improving  Mathematics.  —  Effects  of  the  exclusive 
Study  of  Mathematics. — How  obviated. 

The  most  important  point,  in  commencing  the  study 
of  any  branch  of  Mathematics,  is,  to  obtain  precise  and 
accurate  views  of  the  fundamental  principles  and  the  im- 
port of  the  symbols,  in  order  to  which  the  nature  of  the 
things  must  be  considered,  apart  from  the  definitions. 

The  principal  defects  against  which  the  student  should 
be  on  his  guard,  are,  vague  or  inaccurate  definitions  and 
sophistical  reasoning.  Although  mathematical  demon- 
strations profess  to  establish  the  conclusions  beyond  the 
possibility  of  any  doubt  or  uncertainty,  yet  they  some- 
times fail  to  do  so,  more  especially  in  the  higher  depart- 
ments, in  which  they  occasionally  establish  only  a  prob- 
ability. Consequently  the  student  should  ascertain  how 
far  the  demonstration  extends,  and  distinguish  what  is 
proved  from  what  is  not. 

Wherever  there  is  a  choice,  the  learner  should  prefer 
the  most  general  methods,  as  they  are  the  most  compre- 
hensive and  powerful.  This  will  both  save  time,  and  en- 
able him  to  master  difficulties  which  are  not  easily  sur- 
mounted without  such  aids.  He  should,  therefore,  ob- 
tain a  good  knowledge  of  the  Higher  Analysis,  which 
presents  no  serious  peculiar  difficulty,  and  which  is  very 
superior  to  the  comparatively  feeble  and  prolix  methods 
of  the  older  mathematicians. (22) 

Attention  to  the  symmetry  and  regularity  of  expres- 
sions is  an  important  means  of  discovering  the  more  gen- 
eral laws :  and  it  may  be  said  with  truth  that  a  proper 
series  of  symbols,  and  a  due  arrangement  of  terms,  are 


348  MATHEMATICS.  [CHAP.  XXII. 

equally  advantageous  to  the  student  and  the  original  in- 
vestigator. 

Those  propositions  which  are  either  necessary  links  in 
the  chain  of  demonstration,  or  valuable  for  their  applica- 
tions, are  amply  sufficient  for  the  purposes  both  of  men- 
tal discipline  and  practice;  and  the  student  should  be- 
ware of  spending  much  time  on  the  endless  list  of  curi- 
ous problems  of  no  application.  Indeed  particular  prob- 
lems and  examples  should  occupy  little  time,  and  be  em- 
ployed merely  as  elucidating  theorems,  which  is  general- 
ly their  only  real  use.  The  practical  problems  which  oc- 
cur in  the  sciences  and  arts  based  on  Mathematics  form 
the  best  exercise,  either  for  mental  discipline  or  the  at- 
tainment of  readiness  and  skill  in  calculation.  Working 
problems  mechanically,  by  rules  whose  real  character  is 
not  known,  stultifies  the  mind  almost  as  much  as  repeat- 
ing by  rote  demonstrations  which  are  not  understood. 

In  Arithmetic,  every  expression  and  result  is  viewed 
as  positive :  but,  in  Algebra,  the  case  is  frequently  oth- 
erwise, because  the  precise  nature  of  the  problems  or  of 
the  quantities  sought  may  not  be  clearly  understood  at 
the  outset,  or  the  problem  admits  of  several  symmetrical 
solutions. 

We  can  always  understand  the  precise  signification  of 
an  isolated  negative  quantity,  such  as  —a,  by  remember- 
ing the  self-evident  truth  that  +a—a  (or  a  —  a)  —  0: 
and,  therefore,  if  we  know  what  a  or  -\-a  signifies,  we 
need  have  no  difficulty  in  understanding  what  —  a  means: 
for  we  must  interpret  it  so  that,  when  we  prefix  -+•«,  we 
arc  brought  to  0,  zero,  or  the  starting  point,  which  is 
well  known,  and  through  which  we  pass,  in  going  from 
-j-  to  —  or  the  reverse. 

The  learner  is  apt  to  be  puzzled  by  assuming  that  —  a 
denotes  a  quantity  less  than  nothing,  whereas  it  denotes 
the  same  amount  as  -j-«,  but  taken  reversely.  Thus,  if 
-fa  mean  such  a  distance  from  a  certain  line  measured 
to  the  right,  —a  means  that  distance  measured  from  the 
same  line  to  the  left :  if  the  former  mean  so  much  meas- 
ured upward,  the  latter  means  so  much  measured  down- 
ward, and  so  on. 

In  Algebra  -f-  often  means  simply  that  the  quantity  to 
which  it  is  prefixed  is  measured  in  a  certain  direction, 
and  — ,  that  it  is  measured  in  a  contrary  direction.  The 
former  sign  is  prefixed  to  the  quantities  which  nre  deem- 


SEC.  3.]  STUDY  OF  MATHEMATICS.  349 

ed  additive,  positive  or  increasing,  being  those  which 
were  first  considered  ;  and  the  latter  is  prefixed  to  those 
which  are  deemed  subtractive,  negative  or  decreasing, 
being  those  which  come  into  view  in  examining  the  less 
obvious  aspects  of  the  proposition.  But,  so  far  is  this 
from  indicating  absolute  addition  or  subtraction,  that  the 
signs  might  frequently  change  places,  without  any  incon- 
venience. Thus,  in  Analytical  Geometry,  distances  to 
the  right  of  the  vertical  co-ordinate  are  indicated  by  +, 
and  those  to  the  left  by  — ,  evidently  because  we  write 
and  read  towards  the  right:  but  had  the  science  orig- 
inated with  those  Asiatics  who  write  and  read  the  other 
way,  they  would  probably  have  reversed  this  use  of  the 
signs ;  and  this  would  be  naturally  as  proper  as  our 
method. 

The  student  must  not  confound  abstract  with  concrete 
numbers,  nor  attempt  to  apply  to  the  former  what  prop- 
erly belongs  only  to  the  latter.  All  abstract  numbers 
are  essentially  positive :  and,  therefore,  to  speak  of  multi- 
plying one  abstract  number  —a  by  another  abstract  num- 
ber — #,  is,  to  heap  one  absurdity  upon  another,  because 
abstract  numbers  less  than  nothing  cannot  exist.  But 
when  we  come  to  concrete  numbers,  or  those  which  de- 
note quantities  measured  in  a  certain  way,  or  particular 
kinds  of  quantity,  the  case  is  greatly  altered ;  and  we 
must  then  apply  the  properties  of  abstract  numbers  only 
so  far  as  they  hold  good. 

In  dealing  with  concrete  numbers,  we  are  not  bound 
to  stop  at  the  zero  or  starting  point,  because  quantity 
exists  equally  on  both  sides  of  it ;  and  we  may  proceed 
on  one  side  as  well  as  the  other,  only  indicating  on  which 
side  the  quantities  lie,  by  prefixing  -f  to  the  one,  and  — 
to  the  other.  In  abstract  numbers,  on  the  other  hand, 
we  cannot  pass  zero :  for,  when  we  reach  that,  our  quan- 
tities wholly  vanish.  Concrete  numbers  are  employed 
upon  certain  assumptions  made  at  the  outset,  the  nature 
of  which  must  be  marked  and  attended  to,  if  we  would 
avoid  confusion  and  error,  whereas  no  such  assumptions 
can  be  legitimately  made  in  regard  to  abstract  numbers. 
In  order  to  render  demonstrations  and  processes  relating 
to  concrete  numbers  perspicuous  and  valid,  they  must 
conform  to  the  restrictions  imposed  by  the  particular  as- 
sumptions made. 

Even  those  expressions  which  might  appear  to  defy 


350  MATHEMATICS.  [CiiAP.  XXII. 

every  attempt  to  assign  them  a  clear  and  definite  signifi- 
cation, become  quite  intelligible,  when  their  origin  and 
nature  are  clearly  understood.  Such  are,  the  square  roots 
of  negative  quantities,  which  are  termed  imaginary  or 
impossible,  and  which  may  all  be  reduced  to  the  form 
a^/ — 1.  These  arise  from  some  inconsistency  or  impos- 
sibility, involved  in  the  problem  whence  they  originate ; 
and  the  result  shows  the  nature  of  the  absurdity,  and 
how  the  problem  must  be  modified,  in  order  to  remove  it. 
A  consideration  of  the  origin  and  real  import  of  such  ex- 
pressions shows  that  they  may  be  employed  in  opera- 
tions like  others,  that  they  are  to  be  interpreted  accord- 
ing to  the  nature  of  the  problem  in  which  they  occur, 
and  that,  when  they  disappear  from  an  equation,  the  re- 
sult is  not,  in  the  least,  vitiated  by  their  having  entered 
into  the  operation. 

Analytical  Geometry  possesses  over  the  Synthetical 
the  advantages  of  greater  generality  and  conciseness,  and 
of  furnishing  means  of  testing  hypotheses  and  evolving 
consequences  with  much  greater  facility.  Hence  it  is 
usually  preferable  even  in  those  cases  where  the  synthet- 
ical is  applicable,  while,  in  many  cases,  the  latter  is  quite 
useless.  Yet  it  furnishes  the  only  means  of  establishing 
the  principal  propositions  of  Elementary  Geometry;  and 
it  affords  more  concise  and  elegant  demonstrations  of 
particular  propositions  than  the  other. 

As  Mathematics  are  independent  of  observation,  ex- 
periment, or  testimony,  they  can  be  extended  and  im- 
proved chiefly  by  means  of  indirect  discovery  and  inven- 
tion, the  only  exception  being,  where  a  discovery  is  made 
accidentally,  while  performing  a  process.  The  higher  de- 
partments admit  of  indefinite  extension  :  yet,  as  the  field 
is  already  very  wide,  it  is  desirable  that  what  is  known 
should  be  generalized,  abridged  and  elucidated,  before 
we  are  required  to  proceed  much  farther.  It  sometimes 
happens,  however,  that  new  discoveries  totally  supersede 
more  tedious  and  feeble  methods  previously  in  use :  and 
we  cannot  have  too  many  discoveries  of  that  kind  ;  for 
they  abbreviate  the  sciences,  while  they  render  them 
more  powerful  in  their  application.  Testing  hypotheses 
analytically  forms  one  of  the  principal  instruments  of 
progress  in  this  direction. 

The  exclusive  study  of  Mathematics  naturally  tends  to 
produce  credulity,  scepticism,  one-sided  views,  and  a  hab- 


SEC.  1.]  PHYSICAL  SCIENCES.  351 

it  of  regarding  mere  expressions,  without  paying  suffi- 
cient attention  to  what  they  denote.  Moreover,  as  Math- 
ematics exercise  no  influence  on  the  feelings  or  morals, 
those  who  study  nothing  else  are,  so  far  as  these  are  con- 
cerned, on  a  level  with  those  who  study  nothing.  But 
such  tendencies  are  completely  obviated  by  studying  the 
organical  and  mental  sciences.  The  mechanical  and  ethe- 
real sciences  hardly  furnish  a  sufficient  antidote,  on  ac- 
count of  their  close  resemblance  to  Mathematics. 


CHAPTER  XXIII. 

OF   THE   PHYSICAL    SCIENCES. 

§  1.  OP  THE  PHYSICAL,  SCIENCES  IN  GENERAL. — Differences  between 
Physics  and  Mathematics. — Of  what  the  former  consist,  and  on 
what  based. — Directions  for  Study. — General  Uses  of  Physics. 

THIS  class  of  sciences  differs  essentially  from  Mathe- 
matics in  being  based  on  physical  realities,  instead  of  ab- 
stract quantities  and  definitions.  Their  fundamental 
principles  are  learned  chiefly  from  experience  and  testi- 
mony ;  and  consequently  they  extend  only  to  the  present 
system  of  nature,  and  their  truths,  although  general,  are 
only  contingent,  without  possessing,  to  any  great  extent, 
the  universality  of  Mathematics?  They  consist  mostly 
of  inductions  regarding  material  objects,  and  inferences 
from  these  inductions.  Observations  or  experiments  are 
generally  required  to  establish  the  primary  inductions ; 
and  in  many  cases,  these  require  to  be  numerous,  and 
made  with  much  care  and  skill. 

In  studying  these  sciences,  we  should  test  the  proofs 
on  which  the  professed  primary  inductions  rest,  as  some 
of  those  stated  in  several  books  are  false.  Besides  guard- 
ing against  vague  and  erroneous  definitions  and  sophist- 
ical reasoning,  as  in  Mathematics,  the  student  must  fur- 
ther beware  of  undue  assumptions  and  fallacies  of  testi- 
mony. The  definitions  also  require  a  more  careful  consid- 
eration than  in  Mathematics,  as  they  may  fail  to  express 
the  essential  peculiarities  of  the  things  defined,  or  to  con- 
vey a  correct  and  adequate  notion  of  them,  because  they 
are  much  more  complex  and  difficult  to  understand  than 
mathematical  quantities. 


352  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

The  physical  sciences  give  us  accurate,  although  inad- 
equate, views  of  nature  and  its  Eternal  Ruler.  Hence  a 
knowledge  of  them  tends  to  banish  superstition,  and  to 
strengthen  the  foundations  of  true  religion.  They  also 
improve  the  faculty  of  observation,  and  teach  us  to  look 
carefully  to  our  premises,  as  well  as  to  our  inferences,  so 
that  they  supply  the  most  striking  defect  of  Mathemat- 
ics, as  an  instrument  of  intellectual  discipline.  They  also 
furnish  many  truths  which  are  employed  in  the  mental 
sciences,  while  their  applications  in  the  arts  are  innumer- 
able. 

§  2.  OF  THE  MECHANICAL  SCIENCES. — How  these  are  to  be  studied. 
— (1)  Mechanic. — Friction,  and  Strength  of  Materials. — (2)  Hy- 
dric. — Inaccurate  Definition. — Cohesion  and  Friction  of  Liquids. 
— (3)  Pneumatic. — (4)  Acoustic. — (5)  Astronomy. — Means  of  as- 
certaining its  Conclusions. — Difficulties. — Law  of  Gravitation. — 
Distinction. — Tables. — Eclipses. — Masses. 

This  class  resembles  Mathematics  so  much  that  most 
of  what  was  said  regarding  these,  is  equally  applicable 
here.  But  there  is  occasion  for  more  attention  to  the 
fundamental  principles,  which  are  much  more  liable  to 
be  fallacious  than  those  of  Mathematics,' while  there  is 
less  danger  of  our  time  being  thrown  away  on  futile  in- 
vestigations. Yet  it  is  possible  to  miss  the  most  inter- 
esting and  important  parts  of  the  subject,  by  dwelling 
too  long  on  others.  There  are  various  curious  problems 
in  Mechanic,  for  example,  that  might  not  unjustly  be 
classed  with  the  magic  squares  and  Diophantine  Analy- 
sis of  the  old  mathematicians,  and  which  it  would  be  very 
improper  to  study,  to  the  exclusion  of  Astronomy. 

1.  Mechanic  is  based  partly  on  intuitions,  and  partly  on 
simple  observation  and  experiment,  but  more  on  the  last 
than  on  the  second.  The  force  of  terrestrial  gravity  is 
accurately  determined  by  means  of  Atwood's  falling  ma- 
chine ;  the  velocity  of  projectiles  can  be  approximately 
measured  by  the  ballistic  pendulum;  and  the  laws  of 
equilibrium  are  established  or  confirmed  by  numerous 
experiments  with  weights, levers,  pulleys,  screws,  inclined 
planes,  &c.(23) 

Most  of  the  manual  arts  are,  more  or  less,  dependent 
on  Mechanic,  which  also  forms  the  chief  foundation  of 
the  other  mechanical  sciences,  and  is  of  frequent  applica- 
tion in  the  organical  and  geographical  sciences. 

A  very  important. part  of  this  science  is,  that  which 


SEC.  2.]  MECHANICAL  SCIENCES.  353 

treats  of  friction  and  the  strength  of  materials,  things 
which  can  be  properly  determined  only  by  numerous 
careful  experiments.  Many  lives  have  been  lost,  and 
much  property  has  been  destroyed,  owing  to  ignorance 
or  erroneous  views  of  these  subjects. 

2.  Hydric  adopts  the  conclusions  of  the  preceding  sci- 
ence, and  derives  its  other  primary  premises  chiefly  from 
observation  and  experiment.     The  specific  gravity  of  liq- 
uids can  be  accurately  ascertained  by  means  of  the  hy- 
drometer ;  the  laws  of  their  motions  are  deduced  from 
observations  on  streams,  and  experiments  with  tubes,  ar- 
tificial canals,  and  vessels  from  which  water  is  made  to 
issue  through  an  orifice.     Reasoning,  apart  from  experi- 
ence, is  of  comparatively  little  avail  in  this  science :  yet, 
by  combining  the  results  of  experiments  and  mathemat- 
ical principles,  much  may  be  learned  that  is  of  great  use 
in  the  construction  of  pumps,  fire-engines,  and  water- 
works, including  canals,  and  also  in  determining  the  best 
forms  of  ships  and  their  moving  apparatus,  as  well  as  the 
best  methods  of  loading  and  working  them. 

A  liquid  has  been  frequently  defined  "  a  substance  which 
communicates  pressure  equally  in  every  direction."  But 
this  definition  is  inaccurate :  for  it  is  applicable  only  to  a 
fluid  whose  particles  are  totally  destitute  of  cohesion, 
which  is  not  the  case  with  any  known  liquid,  nor  espe- 
cially with  water,  the  principal  liquid  of  which  we  have 
any  knowledge.  The  drops  pendent  from  the  fingers, 
after  being  dipped  in  it,  prove  that  its  particles  cohere  ; 
and  as  these  are  larger  as  the  water  becomes  colder  and 
denser,  it  appears  that  the  force  of  cohesion  varies  with 
the  temperature. 

The  fact  that  all  liquids  possess  friction,  has  been  some- 
times overlooked,  although  this  property  exerts  an  ex- 
tensive influence  on  their  motions.  Owing  to  this,  and 
the  preceding  erroneous  definition,  the  actual  motions  of 
liquids  are  widely  different  from  what  the  theories  of 
several  writers  on  this  subject  indicate:  and  the  influence 
of  cohesion  and  friction  must  be  accurately  ascertained 
before  Hydric  can  approach  perfection. 

3.  The  principles  of  Pneumatic  are  based  on  Hydric, 
and  experiments  made  with  the  thermometer,  barometer, 
condenser,  pressure-gauge,  and  eudiometer.     It  consists 
mostly  of  primary  facts,  and  contains  few  long  chains  of 
reasoning.     The  subject  of  cohesion  cannot  cause  any 


354  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

difficulty  here,  as  the  particles  of  all  gaseous  bodies  or 
aeriform  fluids  are  strongly  repelled :  but  this  renders 
the  influence  of  friction  very  extensive ;  and  the  extreme 
rapidity  with  which  their  density  changes,  with  slight 
variations  of  temperature,  increases  the  difficulty  of  de- 
termining their  movements,  otherwise  than  by  direct  ob- 
servation or  experiment. 

The  great  importance  of  air,  as  a  prime  necessary  of 
life,  and  its  extensive  agency  in  many  of  the  most  inter- 
esting phenomena  of  physical  nature,  render  this  science 
as  important  as  it  is  beautiful.  To  it  chiefly  belong  the 
properties  of  steam,  and  the  principles  of  the  steam-en- 
gine. 

4.  Acoustic  is  based  chiefly  on  Pneumatic,  the  well- 
known  phenomena  of  hearing,  and  experiments  made  on 
sonorous   substances    and  the   transmission    of  sounds 
through  various  bodies.     It  is  less  extensive  than  the 
preceding  science :  yet  the  importance  of  hearing,  the 
singular  phenomena  of  vibrating  strings  and  surfaces, 
and  its  applications  to  determine  the  proper  forms  and 
arrangement  of  rooms  for  public  speaking,  render  it  both 
interesting  and  curious.     It  also  derives  an  extraneous 
importance  from  the  light  which  it  throws  on  the  ether- 
eal sciences.     To  it  also  belong  the  theory  of  Music  and 
the  vibrations  of  sounding  bodies,  which  reveal  several 
remarkable  peculiarities  of  solid  bodies,  not  discoverable 
otherwise. 

5.  The  immensity  and  grandeur  of  its  subjects  vindi- 
cate for  Astronomy  the  conspicuous  place  which  it  has 
always  held  among  the  physical  sciences :  for  it  treats, 
not  only  of  worlds,  but  of  countless  systems  of  worlds, 
at  distances  of  which  we  can  form  no  adequate  concep- 
tion.    The  astounding  magnitude  of  the  Sun,  the  all-dis- 
solving heat  and  intolerable  glare  of  light  on  its  surface, 
its  huge  swift-rolling  waves  of  fluid  fire,  and  its  vast  ever- 
varying  Tartarean  shades,  form  most  sublime  subjects  of 
contemplation.     Nor  is  this  science  devoid  of  practical 
applications.     Without  its  aid,  it  is  impossible  to  navi- 
gate the  ocean  in  safety,  to  ascertain  the  positions  of 
places  on  the  Earth,  to  determine  the  hour  of  the  day,  or 
the  proper  time  for  cultivating  the  fields,  or  even  to  ob- 
tain a  permanent  standard  of  weights  and  measures. 

This  extensive  science  is  based  on  numerous  observa- 
tions, made  with  instruments  constructed  with  great- 


SEC.  2.]  ASTRONOMY.  355 

est  attainable  accuracy,  and  used  with  the  utmost  care, 
skill  and  dexterity.  Inferences  are  then  drawn  from  the 
observations,  by  means  of  Mathematics,  Dynamic  and 
Optic,  a  competent  knowledge  of  which  is  indispensable 
to  the  successful  study  of  the  heavens. 

By  means  of  a  transit  instrument,  and  a  clock  which 
shows  sidereal  or  star  time,  the  astronomer  finds  the  me- 
ridian altitude  and  time  of  culmination  of  such  bodies  as 
occupy  the  same  apparent  places  for  any  considerable 
period ;  and  this  determines  their  apparent  positions  on 
the  celestial  sphere.  The  altitude  and  azimuth  instru- 
ment, or  an  equatorial,  enables  him  to  ascertain  the  ap- 
parent position  of  an  object  which  is  not  on  the  meridian. 

The  telescopes  and  micrometers  which  form  a  part  of 
those  instruments,  enable  the  observer  to  measure  very 
accurately  the  apparent  size  of  such  bodies  as  exhibit  any 
disc  or  visible  surface,  and  also  to  ascertain  their  appear- 
ances. By  observing  from  day  to  day,  or  from  hour  to 
hour,  the  places  of  those  objects  which  change  their  rela- 
tive positions,  their  apparent  paths,  as  well  as  their  vary- 
ing phases,  are  exactly  determined,  whence  their  real 
motions  are  ascertained  by  forming  hypotheses,  and  test- 
ing them  by  the  proper  criterions.  It  is  thus  found  that 
the  phenomena  accord  only  with  the  supposition  that 
the  planets,  including  the  Earth,  have  a  diurnal  motion 
on  their  axes,  and  another  around  the  Sun,  while  the  sat- 
ellites revolve  round  their  respective  primaries — that  the 
Sun  also  revolves  on  its  axis  and  slowly  round  a  very 
distant  center — and  that  many,  if  not  all,  the  fixed  stars 
have  a  similar  motion  in  space,  although  they  are  too  re- 
mote to  ascertain  whether  they  have  any  diurnal  motion. 

The  distances  of  the  heavenly  bodies  maybe  ascertain- 
ed by  measuring  the  differences  in  their  apparent  posi- 
tions when  viewed  from  two  points  of  the  Earth's  sur- 
face or  orbit,  whose  distances  from  each  other  are  known, 
the  mean  radius  of  the  Earth  or  of  its  orbit  being  adopt- 
ed as  the  unit  of  measure.  The  process  is  the  same  as 
that  by  which  we  ascertain  the  distance  of  a  terrestrial 
object,  when  we  take  the  angles  which  it  forms  with  a 
line  of  known  length,  measured  from  the  two  extremities 
of  the  line.  In  each  case,  we  have  a  side  and  the  three 
angles  of  a  triangle,  to  find  the  other  sides,  which  is  very 
easily  done,  from  the  well-known  theorem  that  the  sides 
are  proportional  to  the  sines  of  the  opposite  angles.  Th.e 


356  PHYSICAL  SCIENCES.      [CHAP.  XXIIL 

only  difficulty  lies  in  making  the  measurements  with  suf- 
ficient accuracy. 

When  once  we  know  the  Earth's  distance  from  the  Sun, 
that  of  any  other  planet  from  the  Sun  is  readily  ascer- 
tained from  the  law  that  the  squares  of  the  times  of  their 
revolutions  round  the  Sun,  are  proportional  to  the  cubes 
of  their  mean  distances,  a  law  which  is  a  necessary  con- 
sequence of  those  of  motion  and  gravitation. 

The  distance  and  apparent  or  angular  magnitude  of  a 
heavenly  body  being  known,  it  requires  only  the  solution 
of  the  simplest  problem  in  Trigonometry  to  determine 
its  real  diameter :  for  Radius- is  to  the  sine  of  half  the  an- 
gle of  apparent  magnitude,  as  the  distance  is  to  the  semi- 
diameter.  But  this  method  is  inapplicable  to  the  fixed 
stars,  because  they  show  no  discs ;  and  their  magnitudes 
can  only  be  conjectured  from  comparing  the  amount  of 
light  which  they  give  with  that  which  the  Sun  would 
impart  at  the  same  distance,  the  brilliancy  of  a  body  va- 
rying inversely  as  the  square  of  its  distance. 

Even  this  loose  method  fails  in  the  case  of  most  of  the 
fixed  stars,  because  they  are  so  remote  that  their  dis- 
tances cannot  be  ascertained  even  approximately,  as  the 
diameter  of  the  Earth's  orbit  bears  no  measurable  pro- 
portion to  their  distances.  It  is  also  to  be  observed  that 
no  astronomical  quantity  admits  of  being  measured  with 
as  much  accuracy  as  terrestrial  magnitudes :  a  close  ap- 
proximation is  all  that  can  generally  be  attained ;  and, 
not  unfrequently,  we  can  obtain  only  a  loose  approxima- 
tion, as  in  the  case  of  the  distances  of  fixed  stars. 

After  ascertaining  the  distances,  magnitudes,  and  real 
motions,  of  the  members  of  the  solar  system,  the  laws  of 
the  forces  that  control  these  motions  are  ascertained  by 
comparing  them  with  those  which  determine  the  motions 
of  a  common  projectile,  and  employing  the  ordinary  laws 
of  motion,  and  the  principles  of  Mathematics,  in  deducing 
the  consequences  necessarily  implied  in  the  phenomena. 
This  process  was  first  applied  to  the  Moon,  then  extend- 
ed to  the  Earth's  motions  around  the  Sun,  and  after- 
wards to  the  other  planets. 

Thus  was  established  the  law  of  gravitation,  which  ac- 
counts for  all  the  motions  of  those  bodies,  and  enables 
the  astronomer  to  determine  the  perturbations  of  the 
planets,  or  the  irregularities  in  their  movements  caused 
by  their  mutual  influence  on  each  other,  so  that  their  fu- 


SEC.  2.]  ASTRONOMY.  357 

ttire  positions  can  be  accurately  ascertained,  and  laid 
down  in  tables.  It  is  observable,  however,  that  the  law 
only  expresses  the  fact  of  the  existence  of  a  certain  force, 
and  the  modes  in  which  its  influence  varies :  it  gives  no 
explanation  whatever  of  the  origin  or  real  nature  of  the 
force. 

When  once  accurate  tables  have  been  constructed,  the 
future  places  and  phases  of  the  bodies  can  be  found  with 
comparatively  little  labor,  as  we  are  furnished  with  all 
the  principal  elements  of  the  calculation,  ready  for  use. 
Thus,  if  we  wish  to  ascertain  the  number  and  character- 
istics of  the  eclipses  that  will  occur  next  year,  we  first 
ascertain  the  positions  of  the  Sun  and  Moon  at  its  com- 
mencement. Then  from  the  motions  of  these  bodies  in 
their  orbits,  as  given  by  the  tables,  we  ascertain  how  oft- 
en the  Moon  will  pass  through  the  Earth's  shadow,  and 
the  Moon's  shadow  strike  the  Earth,  till  the  end  of  the 
year.  The  former  will  be  the  number  of  lunar,  and  the 
latter,  of  solar,  eclipses. 

The  ordinary  rules  of  Trigonometry  enable  us  to  de- 
termine the  times  and  peculiarities  of  the  various  eclipses, 
from  knowing  the  relative  positions  of  the  Earth  and  the 
Moon,  when  the  phenomena  occur.  Those  peculiarities 
depend  on  the  distances  of  the  Earth  from  the  Sun  and 
Moon,  and  the  latter's  position  in  its  orbit.  Thus,  in  cal- 
culating a  solar  eclipse,  the  size  of  the  Moon's  shadow, 
at  the  Earth's  distance,  is  wholly  determined  by  their  re- 
spective distances  from  the  Sun ;  and  the  particular  parts 
of  the  Earth  which  the  shadow  will  cross,  can  be  ascer- 
tained from  the  position  of  the  Moon's  node,  at  the  time 
of  conjunction,  while  the  duration  of  the  eclipse  is  read- 
ily found  from  knowing  the  velocity  of  the  Moon  in  its 
orbit. 

Knowing  the  Earth's  distance  from  the  Sun  and  Moon, 
and  the  latter's  course  and  velocity  in  its  orbit,  the  laws 
of  motion  and  gravitation  enable  us  to  determine  the  pro- 
portion which  the  Earth's  mass  or  weight  bears  to  the 
Sun's,  the  latter  being  adopted  as  the  unit  of  measure. 
The  problem  may  be  otherwise  solved  by  comparing  the 
influence  of  the  Earth  on  a  falling  body  with  that  of  the 
Sun  on  the  Earth.  In  the  case  of  those  planets  which 
are  accompanied  by  satellites,  their  masses  are  ascertain- 
ed by  comparing  their  influence  on  these  with  that  of  the 
Sun,  either  on  themselves  or  on  their  satellites.  The 


358  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

masses  of  those  planets  which  have  no  satellite,  are  ascer- 
tained approximately,  by  observing  the  perturbing  influ- 
ence which  they  produce  on  some  other  body,  whether 
planet  or  comet.  The  masses  of  the  satellites  are  ascer- 
tained from  the  perturbations  in  their  motions  produced 
either  by  the  Sun  or  by  each  other.  That  of  the  Moon 
may  be  farther  ascertained  from  its  effects  in  changing 
the  Earth's  axis,  and  its  comparative  influence  on  the 
tides.  (24) 

§  3.  OF  THE  ETHEREAL  SCIENCES. — General  Character  of  these  Sci- 
ences.— Their  special  Use  as  a  Study. — (1)  Optic. — Origin  and 
probable  nature  of  Light. — (2)  Thermotic. — Ultimate  Source  of 
Heat. — (3)  Electric. — Origin  of  Electricity. — Electrostatic. — Gal- 
vanism. —  Magnetism.  —  Electromechanism. — Probable  Nature  of 
Heat  and  Electricity. — Connection  of  these  Sciences. 

These  sciences  resemble  the  mechanical  in  deducing 
numerous  inferences  from  the  primary  facts,  by  means  of 
Mathematics :  but  they  differ  from  those,  as  well  as  from 
all  the  other  physical  sciences,  in  their  subjects  being  of 
a  more  subtile  nature,  and  less  apprehensible  by  our 
senses.  Consequently  they  are  based  much  more  on  ex- 
periment than  on  simple  observation ;  and  great  care  is 
requisite  in  establishing  the  primary  inductions.  Owing 
to  their  resemblance  and  close  connection,  they  exten- 
sively aid  and  illustrate  each  other :  and  the  true  source 
and  nature  of  their  phenomena  require  to  be  understood, 
in  order  to  surmount  some  of  the  difficulties  which  they 
present  to  the  investigator. 

The  study  of  these  sciences  is  an  important  means  of 
enabling  us  to  form  accurate  views  of  nature ;  and  a 
knowledge  of  them  is  indispensable  to  right  conceptions 
of  the  general  structure  and  laws  of  the  material  crea- 
tion. An  exclusive  attention  to  the  mathematical  and 
mechanical  sciences  tends  to  make  us  estimate  every- 
thing by  its  mass,  firmness  or  momentum.  But  a  knowl- 
edge of  the  ethereal  sciences  reveals  to  us  that  the  forces 
which  immediately  control  nature  reside  in  those  things 
which  are  least  perceptible  to  our  senses,  and  apparently 
the  most  feeble  and  inefficacious.  We  are  thus  led  to 
understand  how  invisible  and  impalpable  mind  is  the 
ultimate  source  of  all  power. 

1.  A  knowledge  of  Optic  is  requisite  in  order  to  the 
proper  construction  of  optical  instruments,  while  it  is  an 


SEC.  3.]  ETHEREAL  SCIENCES,  359 

important  means  of  enabling  us  to  preserve  or  improve 
the  sight.  The  wide  range  of  vision,  and  its  necessity  to 
our  very  existence,  consequently  render  this  science  of 
the  utmost  importance,  while  the  properties  of  light  and 
color  are  such  as  to  render  it  one  of  the  most  beautiful 
and  interesting  of  all  the  physical  sciences.  Moreover, 
by  transmitting  polarized  light  through  transparent  bod- 
ies, we  can  ascertain  peculiarities  in  their  structure  which 
can  be  discovered  by  no  other  means. 

The  composition  of  white  light  is  ascertained  by  sim- 
ply passing  it  through  a  common  glass  prism ;  and  other 
fundamental  principles  are  established  with  the  aid  of 
reflecting,  refracting,  polarizing,  and  discolorable  sub- 
stances, of  various  forms  and  kinds.  The  intensity  or 
amount  of  light  is  measured  approximately,  by  means  of 
a  photometer ;  and  its  velocity  is  ascertained  both  from 
astronomical  phenomena  and  from  direct  experiment. 

Light  appears  to  consist  of  undulations,  or  small  waves, 
generated  by  a  rapid,  vibratory  motion  of  the  luminous 
body's  atoms,  and  propagated  through  ether,  in  every  di- 
rection. The  theory  that  it  consists  of  solid,  unconnect- 
ed particles,  which  fly  from  the  luminous  center,  is  at- 
tended with  various  insuperable  difficulties. 

Not  only  do  the  rays  of  light  sometimes  interfere,  so 
as  to  destroy  each  other,  but  it  is  impossible  that  the 
Sun,  for  example,  could  have  been  throwing  off  such  par- 
ticles, for  any  length  of  time,  without  being  dissipated 
through  the  boundless  void.  It  is  no  answer  to  this  ob- 
jection to  say  that  the  particles  are  extremely  small :  for 
they  must  possess  some  bulk ;  and  the  smaller  their  size, 
the  greater  must  be  their  number,  since  they  exist  simul- 
taneously, at  every  point.  Nor  could  such  rays  move  in 
every  direction,  through  every  point,  without  interfering 
with  each  other  to  a  much  greater  extent  than  they  real- 
ly do. 

It  is  also  impossible  that  the  solar  rays  could  fill  every 
point,.as  they  receded  from  the  Sun,  owing  to  the  rapidly 
increasing  surfaces  of  the  spheres  traversed,  unless  we 
adopt  the  absurd  hypothesis  that  they  regularly  divided 
and  subdivided  as  they  advanced.  Nor  could  such  par- 
ticles permeate  a  great  thickness  of  a  hard  and  dense  sub- 
stance, like  glass,  as  light  actually  does.  It  is  also  in- 
credible that  a  black  substance  should  receive  an  indefi- 
nite number  of  such  particles,  without  furnishing  the 


360  PHYSICAL  SCIENCES.      LCHAi-.  XXIII. 

least  indication  that  any  such  thing  ever  penetrated  it, 
either  by  an  increase  of  weight  or  otherwise.  Moreover 
the  tremendous  momentum  of  such  bodies,  moving  with 
a  velocity  of  nearly  two  hundred  thousand  miles  in  a  sec- 
ond, would  have  destroyed  our  sight,  at  the  very  first 
impulse. 

With  regard  to  what  are  termed  the  chemical,  or  dis- 
coloring rays  of  solar  light,  I  am  aware  that  some  consider 
them  totally  different  from  luminous  rays :  but  there  are 
some  indications  that  they  are  only  luminous  rays,  too 
small  to  affect  our  vision,  under  ordinary  circumstances. 

2.  Therm  otic  is  a  most  important  science,  on  account 
of  the  controlling  influence  of  heat  throughout  the  or- 
ganic creation.     The  changes  of  the  seasons  strikingly 
exhibit  this  influence  on  vegetation ;  and  it  is  equally 
extensive,  though  perhaps  less  obvious,  in  relation  to  liv- 
ing beings.     Thus,  if  the  temperature  of  warm-blooded 
animals  is  reduced  a  little  below  the  natural  standard, 
they  speedily  die,  and  a  like  result  follows  when  their 
temperature  is  raised  a  little  above  the  normal  heat.     A 
variation  from  the  proper  temperature  of  the  different 
parts  of  the  body  is  also  a  fruitful  cause  of  disease  and 
death.     The  extensive  applications  of  heat  in  the  arts 
also  invest  the  subject  of  its  production  wdth  great  inter- 
est, and  render  a  knowledge  of  its  sources  and  laws  of 
great  importance. 

The  most  interesting  questions  in  this  science  are, 
those  which  regard  the  origin,  distribution,  and  influence 
of  heat.  Its  immediate  sources  are  various :  but  they 
all  seem  to  be  ultimately  referable,  like  light,  to  a  vibra- 
tory motion  of  the  atoms  of  the  body  whence  it  pro- 
ceeds. This  may  be  produced  by  chemical  or  electric 
action,  and  by  friction,  or  sudden  and  violent  compres- 
sion. Heat  always  tends  to  dissipate  rapidly  through 
space ;  and  the  circumstances  which  accelerate  or  retard 
its  escape  deserve  a  careful  consideration.  Myriads  have 
lost  their  lives  owing  to  their  ignorance  on  this  subject. 

Several  of  the  laws  of  heat  are  learned  by  simple  ob- 
servation ;  and  others  are  ascertained  by  means  of  the 
thermometer,  pyrometer,  calorimeter,  and  various  reflect-, 
ing,  refracting,  radiating,  conducting,  convecting  and  pol- 
arizing substances. 

3.  The  origin  of  electricity  appears  to  be  referable  to 
the  same  ultimate  cause  as  that  of  heat.     It  is  generally 


SEC.  3.]  ETHEREAL  SCIENCES.  361 

produced  by  friction  or  chemical  action  :  but  it  is  equal- 
ly caused  by  heat.  Its  laws  are  mostly  established  by 
means  of  experiments,  in  which  a  great  variety  of  instru- 
ments is  used,  including  the  common  electric  machine, 
the  galvanic  battery,  the  electroscope,  electrometer,  elec- 
trophorus,  condenser,  proof  plane,  and  galvanometer,  the 
magnet,  and  electromagnetic  apparatus,  of  various  kinds. 

Electrostatic  claims  attention  on  account  of  the  pow- 
erful agency  of  statical  electricity,  both  in  nature  and  in 
the  arts.  A  knowledge  of  it  may  be  said  to  have  divest- 
ed lightning  of  its  terrors,  and,  from  being  a  direful  ene- 
my, converted  it  into  a  useful  servant.  It  not  only  ex- 
plains the  origin  of  lightning  and  thunder,  but  points  out 
the  mode  in  which  we  may  guard  against  danger  from 
the  former,  and  how  statical  electricity  may  be  usefully 
employed  in  the  arts. 

Electrogalvanism,  whose  phenomena  are  produced  by 
continuous  currents  of  electricity,  is  of  much  importance 
on  account  of  its  extensive  application,  both  in  the  arts 
and  in  many  scientific  experiments.  In  chemical  analy- 
sis, for  example,  it  affords  one  of  the  most  powerful  means 
of  decomposing  substances.  It  also  furnishes  the  means 
of  accurately  measuring  very  small  portions  of  time,  and 
determining  the  precise  instant  of  an  occurrence,  by 
means  of  the  chronoscope  and  the  electric  clock,  with 
their  proper  appendages. 

The  phenomena  of  Electromagnetism  arise  wholly  from 
electric  currents:  and  terrestrial  magnetism  appears  to 
consist  of  currents  caused  by  the  varying  action  of  the 
Sun,  during  the  diurnal  revolution,  whence  its  phenome- 
na exhibit  the  same  changes  which  mark  the  weather 
and  the  seasons. 

The  value  of  the  magnet  in  Navigation  renders  this 
branch  of  Electric  one  of  great  importance,  while  it  de- 
rives additional  interest  from  its  application  in  the  treat- 
ment of  many  diseases. 

Electro-mechanism  is  an  important  branch,  on  account 
of  its  various  applications  in  the  arts.  The  invention  of 
the  electro-magnetic  telegraph  forms  an  era  in  the  his- 
tory of  human  intercourse  ;  and  the  application  of  elec- 
tric currents  as  a  source  of  motive  power  becomes  in- 
vested with  great  interest  when  we  consider  that  metals 
must  sometime  supersede  coal,  as  a  source  of  motive 
power. 

Q 


362  PHYSICAL  SCIENCES.      [CHAP.  XXIIL 

As  heat  is  produced,  transmitted,  reflected,  refracted, 
and  polarized,  precisely  like  light,  and  travels  with  near- 
ly the  same  velocity,  we  may  infer  that  it,  also,  consists 
of  undulations  of  ether:  and  the  fact  that  we  can  obtain 
an  indefinite  amount  of  heat  from  a  small  body,  by  means 
of  friction,  leads  to  the  same  conclusion. 

Again,  the  close  connection  and  marked  resemblances 
between  heat  and  electricity,  indicate  that  the  latter  con- 
sists of  ethereal  undulations,  as  well  as  the  former. 

Hence  we  come  to  the  conclusion  that  the  imponder- 
able agents  are  all  essentially  alike,  and  that  their  differ- 
ent phenomena  arise  from  different  kinds  of  undulations. 
This  conclusion  is  strengthened  by  the  close  resemblance 
which  the  various  phenomena  exhibit,  and  the  fact  that 
one  frequently  produces  another.  The  imponderability 
of  all  of  them  leads  to  the  same  conclusion ;  for,  as  the 
weight  is  proportional  to  the  mass,  in  all  ponderable 
bodies,  it  follows  that  we  cannot  add  solid  matter  indef- 
initely to  a  body  without  appreciably  increasing  its 
weight.  The  conclusion  is  further  corroborated  by  the 
fact  that  the  agents  all  follow  the  same  law  of  intensity, 
which  is  uniformly  as  the  inverse  square  of  the  dis- 
tance. (25) 

§  4.  OF  THE  ORGANICAL  SCIENCES. — Characteristics  and  Founda- 
tions of  tins  Class. — Directions  for  Study. — Three  important  Prin- 
ciples.—  Monsters. — ( 1 )  Botany. —  (2)  Zoology.  —  Caution. —  (3) 
Anatomy. — (4)  Physiology. — Hygiene. — Ethnology. — (5)  Pathol- 
ogy.— Proper  Bases  of  the  Medical  Arts. — T\vo  guiding  Principles. 
— Distinction. — Foundations  of  Pathology. 

These  sciences  are  distinguished  from  the  preceding 
by  the  general  absence  of  long  chains  of  reasoning,  as 
they  consist  mostly  of  facts  learned  directly  from  obser- 
vations or  experiments,  which  are  frequently  aided  by 
the  microscope,  electric  action,  chemical  re-agents,  and 
so  forth.  A  few  observations,  made  anywhere,  may  serve 
for  the  foundations  of  most  of  the  inorganical  sciences : 
and  when  these  foundations  are  once  well  laid,  the  rest 
.consists  chiefly  of  simple  deductions.  But  those  now 
under  consideration  sometimes  require  that  the  whole 
world  should  be  ransacked,  in  order  to  furnish  their  ma- 
terials, as  every  country  offers  something  peculiar ;  and 
long  deductions  here  give  place  to  extensive  observa- 
tions, and  a  careful  examination  of  testimonies. 

In  studying  these  sciences,  we  should  observe  for  our- 


SEC.  4.]  OEGANICAL  SCIENCES.  363 

selves,  as  extensively  as  our  circumstances  will  permit. 
This  will  often  enable  us  to  obtain  more  accurate  and 
lively  views  of  the  things  discussed  than  mere  descrip- 
tions afford,  and  possibly  to  correct  the  errors  or  extend 
the  statements  made  in  books.  We  must  be  constantly 
on  our  guard  against  erroneous  testimonies  and  false 
theories,  which  have  been  very  prevalent  in  this  depart- 
ment of  knowledge :  and  we  should  distinguish  the  as- 
certained facts  from  the  plausible,  but  erroneous  hypoth- 
eses Avith  which  they  are  sometimes  blended.  Mathe- 
matics are  much  less  applicable  in  these  sciences  than  in 
the  inorganical,  so  that  they  may  be  studied  to  advant- 
age by  persons  who  possess  only  a  very  limited  knowl- 
edge of  Mathematics. 

The  principles  of  classification  come  frequently  into 
requisition,  and  a  proper  application  of  them  is  gener- 
ally a  matter  of  great  importance,  in  all  these  sciences. 
They  are,  therefore,  well  adapted  for  investigation  by 
those  who  dislike  long  chains  of  reasoning,  and.  delight 
in  observing  and  classifying,  while  they  furnish  a  field 
which  the  united  labors  of  many  generations  will  not 
exhaust. 

In  examining  the  structure  of  minute  parts,  much  aid 
is  derived  from  the  microscope,  which  enlarges  the  power 
of  vision  to  such  an  extent  that  it  may  be  said  to  reveal 
new  worlds :  and  although  these  are  as  diminutive  as 
those  unfolded  by  the  telescope  are  extensive,  yet  they 
possess  over  the  latter  the  great  advantage  of  being  com- 
pletely within  our  reach. 

In  all  the  organical  sciences,  the  following  inductive 
principles  guide  and  assist  investigation. 

(a.)  Every  organ  performs  one  or  more  functions. 
Those  of  some  organs,  such  as  the  eye  and  the  ear,  arc 
easily  ascertained;  and  although  those  of  some  parts  are 
not  so  readily  discovered,  they  may  be  found  out  by  con- 
tinued and  accurate  investigation.  Some  organs,  like  the 
human  tongue,  perform  different  functions ;  and,  there- 
fore, when  we  discover  one,  we  must  not  infer  that  it  is 
the  sole  function. 

(b.)  One  part  of  an  organic  being  harmonizes  with 
every  other  part  •  and  the  whole  fabric  is  adapted  to 
some  particular  mode  of  existence.  Hence  an  inspection 
of  one  part,  as  a  tooth  or  a  foot,  may  enable  us  to  ascer- 
tain the  form  of  another,  and  the  being's  general  struc- 
ture and  mode  of  existence. 


364  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

(c.)  The  corresponding  organs  of  similar  organic  be- 
ings perform  similar  functions.  Hence  when  those  of 
one  organ  are  known,  those  of  the  corresponding  organ 
may  be  ascertained  with  little  difficulty.  The  similarity 
of  functions  is  generally  proportional  to  that  of  the  be- 
ings compared :  and  where  this  is  very  close,  the  func- 
tions are  usually  identical. 

These  principles  do  not,  of  course,  apply  to  monsters 
or  malformations :  but  the  existence  of  such  beings  is  so 
rare  as  not  to  detract  materially  either  from  their  value 
or  their  general  accuracy.  Such  anomalies  are  extreme- 
ly few,  compared  with  the  wide  extent  of  organic  na- 
ture ;  and  even  these  arise  from  some  violation  of  organ- 
ic laws. 

1.  Besides  the  interest  which  it  derives  from  the  im- 
mense variety,  beauty  and  magnificence  of  the  vegetable 
kingdom,  Botany  claims  attention  on  account  of  its  bear- 
ings on  the  necessaries  and  conveniences  of  life.     Not 
only  our  food,  but  also  our  clothing,  is  all  derived  from 
vegetation,  either  directly  or  indirectly.     So  is  a  great 
number  of  the  most  valuable  medicines;  and  the  various 
uses  of  timber  are  well  known.     By  describing  the  qual- 
ities and  peculiarities  of  the  various  kinds  of  plants,  Bo- 
tany assists  us  in  determining  their  character,  the  best 
modes  of  cultivating  such  as  are  useful  or  ornamental, 
and  where  any  required  species  may  be  procured. 

The  facts  of  this  science  are  learned  from  observing 
the  plants  in  their  native  regions,  hot-houses  or  botanical 
gardens,  or  from  examining  preserved  specimens,  and 
from  inspecting  their  minute  structure  with  the  micro- 
scope, while  the  component  elements  are  ascertained  by 
chemical  analysis. (26) 

2.  The  boundaries  between  Botany  and  Zoology  are 
not  very  obvious,  as  some  animals  are  so  low  in  the  scale 
that  they  cannot  easily  be  distinguished  from  plants;  but 
every  being  possessing  thought  is  an  animal ;  and  this 
criterion  is  easily  applied,  as  thought  is  always  accom- 
panied with  the  power  of  voluntary  motion. 

Zoology  describes  the  various  kinds  of  animals,  classi- 
fied according  to  their  organization,  including  their  ap- 
pearance, general  structure,  food,  instincts,  habits,  and  lo- 
calities :  and  a  knowledge  of  it  is  indispensable  to  right 
views  of  the  economy  of  nature.  To  the  interests  of  Bo- 
tany, it  superadds  that  which  is  derived  from  sympathy 


SEC.  4.]  ORGANICAL  SCIENCES.  365 

with  living  beings  possessing  several  faculties  in  common 
with  ourselves,  although  they  are  limited  to  a  compara- 
tively narrow  range.  It  facilitates  a  discovery  of  the 
characteristics  of  a  hitherto  unknown  species,  and  enables 
us  to  determine  the  proper  mode  of  treating  the  low- 
er animals,  many  of  which  have  often  been  destroyed 
through  ignorance,  when  they  ought  to  have  been  care- 
fully preserved. 

The  materials  of  this  very  extensive  science  are  col- 
lected from  direct  personal  observation,  the  reports  of 
travelers,  and  the  descriptions  of  naturalists,  who  lived 
in  the  native  regions  of  the  animals  described,  or  had  ac- 
cess to  some  fair  specimens,  such  as  are  sometimes  found 
in  zoological  gardens.  But  the  proper  criterions  of  tes- 
timony should  be  carefully  applied  to  such  descriptions, 
as  several  of  them  are  blended  with  fables  or  misrepre- 
sentations. 

3.  Anatomy  furnishes  a  striking  illustration  of  the  con- 
summate skill  with  which  everything  throughout  the  or- 
ganic creation  has  been  formed ;  and  it  also  demands  at- 
tention on  account  of  its  connection  with  Physiology, 
Surgery  and  Medicine.     It  is  based  on  careful  dissection, 
aided  by  the  miscroscope,  mercurial  injections,  diluted 
acids  or  alkalies,  &c.     Human  Anatomy  exhibits  a  cor- 
rect view  of  the  most  complex  and  finished  work  of  God 
that  our  eyes  can  behold.     General  and  Comparative 
Anatomy  shows  the  immense  variety  which  prevails  in 
animal  structures,  and  the  numerous  modifications  found 
in  the  same  organ,  adapting  it  to  various  circumstances. 
It  also  enables  us  to  classify  animals  according  to  their 
real  affinities,  which  often  differ  widely  from  apparent 
resemblances. 

4.  Physiology  is  of  the  utmost  importance  on  account 
of  its  connection  with  health,  the  laws  of  which  seldom 
receive  due  attention  from  those  who  are  ignorant  of 
this  science.     Mere  precepts  have  comparatively  little  in- 
fluence on  such  persons,  as  they  readily  evade  what  they 
are  very  unwilling  to  believe.     But  when  they  under- 
stand the  nature  of  their  physical  organization,  and  tho 
serious  injuries  which  it  suffers  from  various  agents  and 
practices  deemed  harmless  by  the  ignorant,  prejudice  can 
no  longer  resist  the  inference,  and  the  rules  of  health 
soon  change  their  habits  for  the  better.     Reckless  ex- 
posure to  deleterious  agencies,  and  habitual  indulgence 


366  PHYSICAL  SCIENCES.      [CHAP.  XXIIT. 

in  health-destroying  practices,  gradually  disappear,  till 
they  vanish:  and  the  delusion  of  supposing  that  the  ef- 
fects of  such  conduct  can  be  obviated  or  speedily  re- 
moved, is  seen  in  its  true  light.  This  science  also  shows 
the  extreme  minuteness  and  perfect  finish  of  the  element- 
ary parts  of  every  tissue.  It  discloses  fibres  compared 
with  which  the  most  slender  filament  that  we  can  see,  is 
a  cable,  and  globules  of  which  it  would  require  millions 
to  form  the  size  of  a  pea. 

The  truths  of  Physiology  are  established  by  means  of 
simple  observations,  and  experiments  of  various  kinds,  in 
which  much  use  is  made  of  the  microscope.  It  also  de- 
rives extensive  aid  from  Chemistry,  Botany,  Zoology  and 
Anatomy,  with  the  last  of  which  it  is  very  closely  con- 
nected. 

Hygiene,  or  that  part  of  Human  Physiology  which  dis- 
cusses the  laws  of  health,  establishes  these  on  the  struc- 
ture and  functions  of  the  various  parts,  and  the  knowl- 
edge derived  from  observation  or  experiment  regarding 
the  modes  in  which  they  are  affected  by  particular  agents 
or  practices.  Health  and  disease  depend  on  causes  which 
act  as  uniformly  as  any  agent  in  the  inanimate  creation ; 
and,  consequently,  wherever  men  fulfil  the  conditions  on 
which  it  depends,  they  will  enjoy  health,  while  they  will 
be  the  victims  of  disease  and  premature  death  as  long  as 
they  violate  these  conditions.  A  knowledge  of  this  part 
of  the  science  is  a  most  important  means,  not  only  of 
preserving  health,  but  also  of  curing  disease,  which  can 
seldom  be  permanently  and  thoroughly  removed,  unless 
we  know  the  conditions  on  which  health  depends. 

Ethnology,  which  discusses  the  origin  and  extent  of 
the  physical  peculiarities  that  distinguish  the  various 
races  of  men,  forms  another  interesting  branch  of  Human 
Physiology.  Detailed  accounts  of  these  peculiarities,  as 
they  are  exhibited  in  different  countries,  properly  belongs 
to  Ethnography. 

5.  The  leading  principles  of  Pathology  are  highly  use- 
ful in  securing  obedience  to  the  laws  of  health,  by  dis- 
closing the  various  lamentable  consequences  which  inev- 
itably result  from  their  continued  violation.  This  sci- 
ence also  forms  a  proper  sequel  to  Human  Anatomy  and 
Physiology,  in  a  course  of  medical  study.  Chemistry 
and  the  organical  sciences  form  the  only  rational  and  sci- 
entific bases  of  the  healing  arts,  which  are  as  apt  to  in- 


SEC.  5.]  PATHOLOGY.  367 

jure  as  to  benefit  while  they  are  merely  empirical,  and 
which  improve  in  exact  proportion  to  the  advancement' 
in  those  sciences. 

The  pathologist  is  guided  by  the  induction  that  mor- 
bid action  obeys  fixed  laws,  like  healthy  functions :  and, 
consequently,  he  can  ascertain  the  causes  of  such  actions, 
and  the  modes  in  which  they  may  be  prevented  or  stop- 
ped, and  their  bad  effects  counteracted  and  removed. 
He  is  also  aided  by  the  induction  that  the  reactions  of 
the  organism,  caused  by  morbific  agencies,  tend  to  pro- 
duce some  beneficial  end:  and  it  is  an  important  object 
to  ascertain  what  that  end  is,  and  how  it  can  be  best  se- 
cured. He  should  distinguish  the  sanitary  action  which 
occurs  in  diseased  parts  from  the  injurious  effects  of  pois- 
onous or  deleterious  agencies,  which  are  of  a  very  differ- 
ent character,  although  they  are  very  apt  to  be  confound- 
ed with  the  former,  because  they  spring  from  the  same 
causes,  and  appear  simultaneously.  While  the  latter 
should  always  be  stopped  and  counteracted  with  as  little 
delay  as  circumstances,  and  a  due  regard  to  other  hy- 
gienic and  pathological  laws,  will  permit,  the  former 
ought  generally  to  be  fostered  and  aided  by  all  proper 
means.  For  their  general  tendency  is,  to  rectify  some 
derangement  or  disorder  in  the  organism. 

This  important  and  extensive  science  is  mostly  estab- 
lished like  Anatomy  and  Physiology :  but  it  has  a  wider 
range,  and  derives  more  aid  from  the  inorganical  and 
geographical  sciences,  because  disease  is  more  varied  in 
its  origin,  phases  and  progress  than  healthy  action.  It 
is  beset  with  difficulties,  whenever  we  pass  beyond  the 
immediate  phenomena ;  and  the  theories  with  which  it 
abounds,  furnish  a  wide  field  of  investigation. 

§  5.  OP  THE  GEOGRAPHICAL  SCIENCES. — General  Character  of  this 
Class. — Directions  for  Study. — (1)  Geography. — (a)  General  Geog- 
raphy.— (h)  Geognosy. — (c)  Hydrology. — (d)  Meteorology. — (2) 
Chemistry. — (3)  Mineralogy. — (4)  Geology. 

These  sciences  treat  both  of  inorganic  and  organic  na- 
ture ;  and  consequently  they  resemble  partly  the  mechan- 
ical and  partly  the  organical.  Although  their  subjects 
are  less  vast  than  those  of  Astronomy,  yet  they  are  not 
only  much  more  within  the  reach  of  our  observation,  but 
also  more  on  a  level  with  our  faculties ;  and  consequent- 
ly their  phenomena  are  apt  to  affect  us  more  powerfully 


368  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

than  the  vaster  scenes  of  that  science.  They  consist  of 
an  immense  mass  of  primary  facts,  based  on  observations 
made  in  different  regions  of  the  globe,  and  of  numerous 
inferences  from  these  facts.  Hence,  in  studying  them, 
we  should  guard  against  fallacies  both  of  testimony  and 
reasoning.  As  personal  observation  enables  us  to  test 
only  a  very  small  portion  of  them,  the  criterions  of  testi- 
mony should  be  applied  with  great  care  and  freedom. 
In  other  respects,  the  remarks  already  made  regarding 
the  study  of  the  other  physical  sciences,  mostly  apply  to 
them.  As  a  whole,  they  offer  a  very  extensive  field  for 
future  discovery. 

1.  The  immense  variety  and  importance  of  its  details, 
and  their  numerous  applications,  render  Geography  a 
very  interesting  subject  of  study ;  and  there  is  hardly 
any  class  of  persons  to  whom  a  knowledge  of  it  is  not 
beneficial. 

(a.)  General  Geography  forms  the  basis  of  all  geo- 
graphical knowledge,  and  is  of  the  greatest  use  in  the 
important  arts  of  Surveying  and  Navigation.  It  is  found- 
ed wholly  on  Mathematics  and  Astronomy.  The  exact 
positions  of  places  on  the  Earth's  surface  are  determined 
by  finding  their  latitudes  and  longitudes,  which  may  be 
done  in  various  ways. 

As  the  elevation  of  the  celestial  pole,  or  immovable 
point  in  the  heavens,  is  necessarily  equal  to  the  latitude 
of  the  place  of  observation,  this  may  be  found  by  taking 
the  greatest  and  least  altitude  of  a  circumpolar  star,  or 
one  which  never  sets :  then  half  the  amount  of  these 
gives  the  latitude,  because  the  greatest  elevation  is  as 
much  higher  as  the  least  is  lower  than  the  pole.  Anoth- 
er simple  means  of  finding  latitudes  is,  by  taking  the  me- 
ridian altitude  of  the  sun  or  a  fixed  star.  As  the  zenith 
distance  of  the  equinoctial  is  equal  to  the  latitude,  and 
the  declinations,  or  distances  from  that  line,  are  given  in 
tables,  a  single  meridian  observation  determines  the  lati- 
tude. 

The  longitude  of  a  place  is  found  by  ascertaining  the 
difference  in  time  between  it  and  the  first  meridian,  or 
that  from  which  longitude  is  reckoned,  and  then  convert- 
ing this  into  degrees,  from  the  proportion  of  15  degrees 
to  an  hour,  every  parallel  revolving  through  360  degrees 
in  24  hours.  One  of  the  most  simple  modes  of  finding 
the  difference  of  time  is,  to  mark  the  hour  on  a  chronom- 


SEC.  5.]  GENERAL  GEOGRAPHY.  360 

eter  which  shows  the  time  at  the  first  meridian,  when  it 
is  noou  at  the  place  of  observation.  This  is  known  by 
the  Sun's  being  then  on  the  meridian,  or  at  the  highest. 
A  more  exact,  but  less  simple  and  easy  method  is,  to  find 
the  time  at  the  first  meridian  from  the  Moon's  distance 
from  some  fixed  star,  with  the  aid  of  tables,  which  give 
the  distances  of  that  luminary  from  many  of  the  fixed 
stars,  at  short  intervals.  The  time  of  the  place  of  ob- 
servation may  be  found  from  one  or  two  altitudes  of  a 
known  fixed  star,  with  the  aid  of  tables.  This  method 
possesses  the  great  advantage  of  being  independent  of 
time-keepers.  Another  simple  and  very  accurate  method 
is,  to  determine  the  difference  of  time  by  means  of  tele- 
graphic signals ;  and  the  use  of  the  electromagnetic  tel- 
egraph renders  this  method  applicable  to  all  places  con- 
nected by  it. 

When  the  positions  of  the  principal  points  have  been 
thus  ascertained,  those  of  others  are  found  by  means  of 
geodetical  surveys,  conducted  on  the  principles  of  spher- 
ical trigonometry,  while  minor  details  are  found  by  means 
of  plane  trigonometry  and  constructions  on  paper.  Maps, 
globes,  and  charts  are  then  constructed,  by  applying  the 
principles  of  perspective,  and  using  the  requisite  mathe- 
matical instruments. 

That  the  Earth  is  either  a  perfect  sphere  or  a  spheroid, 
is  evident  from  the  form  of  its  shadow  on  the  Moon,  dur- 
ing lunar  eclipses,  and  from  the  distance  of  the  visible 
horizon  at  sea  being  always  nearly  proportional  to  the 
elevation  of  the  observer's  eye.  Its  magnitude  may  be 
easily  determined  approximately,  by  measuring  the  an- 
gular depression  of  the  farthest  visible  part  of  the  ocean 
from  a  point  of  known  altitude  above  the  sea  level,  as 
we  have  thus  the  three  angles  and  a  side  of  a  triangle  to 
find  the  other  sides. 

A  more  accurate  method  of  finding  the  form  and  di- 
mensions of  the  Earth,  is,  to  measure  an  arc  of  the  me- 
ridian and  of  the  parallels  of  latitude,  in  different  parts 
of  the  world.  In  order  to  this,  the  difference  of  latitude 
and  longitude  between  two  places  is  accurately  ascer- 
tained ;  and  then  the  distances  between  the  two  meridi- 
ans and  parallels  which  pass  through  them  are  carefully 
measured :  for  it  is  easily  seen  that  these  distances  bear 
the  same  proportion  to  the  circumference  of  the  Earth 
that  the  angular  distances  bear  to  360  degrees,  or  an  en- 

Q  2 


370  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

tire  angular  circumference.  It  is  thus  found  that  the 
Earth  is  a  prolate  spheroid,  whose  respective  diameters 
are  about  7899  and  7925  miles :  in  other  words,  its  form 
and  magnitude  are  those  of  a  solid  generated  by  the  rev- 
olution of  an  ellipse  about  its  conjugate  or  shorter  diam- 
eter, this  being  of  the  former,  and  the  transverse,  or  lon- 
ger, diameter  of  the  latter  length. 

The  absolute  mass,  or  weight,  of  the  Earth  is  ascer- 
tained, approximately,  in  various  ways.  One  is,  by  de- 
termining the  influence  of  a  mountain,  in  deflecting  a 
pendulum  from  the  perpendicular :  but  as  the  weight  of 
the  mountain  and  the  distance  of  its  center  of  gravity 
cannot  be  ascertained  with  any  great  degree  of  accuracy, 
this  method  gives  only  a  rough  approximation.  A  more 
accurate  method  is,  to  determine  the  comparative  force 
of  gravity,  at  different  distances  from  the  Earth's  center, 
in  the  same  vertical  line,  from  the  differences  in  the  vibra- 
tions of  a  seconds  pendulum,  at  the  two  points,  whence 
the  absolute  gravity  of  the  Earth  is  easily  ascertained. 

A  third  method  is,  to  compare  the  torsion  produced 
by  two  large  balls  of  lead  on  two  very  small  ones,  fixed 
on  the  ends  of  a  very  light  rod,  suspended  by  a  very  slen- 
der wire,  and  brought  quite  close  to  the  large  balls.  The 
weight  requisite  to  produce  the  same  amount  of  torsion 
is  easily  ascertained ;  and  thus  the  proportion  which  the 
Earth's  weight  bears  to  the  balls  can  be  ascertained,  to  a 
great  degree  of  accuracy.  The  extreme  minuteness  of 
the  balls  is  compensated  by  their  close  proximity  to  such 
a  degree  as  to  render  their  influence  measurable,  the 
gravitating  force  being  less  as  the  square  of  the  distance 
of  the  body's  center  of  gravity  becomes  greater.  By 
such  means  it  is  found  that  the  Earth  is  about  5^  times 
as  heavy  as  a  globe  of  water  of  its  own  size,  while  the 
Sun's  specific  gravity  is  only  about  Ij. 

(#.)  Geognosy  lies  at  the  foundation  of  several  of  the 
physical  sciences,  while  it  is  indispensable  to  commerce 
and  intercourse  between  remote  nations.  A  knowledge 
of  it  may  also  enable  the  unfortunate  and  distressed  to 
remove  to  a  country  where  they  can  materially  better 
their  condition.  It  is  also  of  great  use  in  the  study  of 
Ethnography  and  History,  which  cannot  be  rightly  un- 
derstood without  its  aid.  It  is  founded  on  the  observa- 
tions of  naturalists,  travelers,  and  mariners,  made  in  the 
various  quarters  of  the  world. 


SEC.  5.]  GEOGRAPHICAL  SCIENCES.  371 

(c.)  Hydrology  is  of  the  utmost  use  in  Kavigation,  and 
furnishes  means  of  extending  our  knowledge  of  Meteor- 
ology and  Geology.  Like  the  preceding  subdivision,  it 
is  based  chiefly  on  observation :  but  the  causes  of  the 
tides  are  investigated  by  means  of  Dynamic  and  Astron- 
omy. These  furnish  a  striking  proof  of  the  Earth's  con- 
nection with  other  members  of  the  solar  system. 

(d.)  Meteorology  is  of  great  importance  in  Hygiene, 
Therapeutic,  Tillage,  and  Navigation.  A  knowledge  of 
the  atmospheric  currents,  combined  with  that  of  oceanic 
currents  and  the  tides,  enables  the  mariner  to  navigate 
the  waters  with  a  degree  of  speed  and  safety  otherwise 
unattainable,  while  the  electromagnetic  telegraph  ren- 
ders the  knowledge  thus  acquired  of  the  utmost  practical 
utility,  by  warning  vessels  of  the  coming  storm,  before 
it  arrives.  So,  an  acquaintance  with  the  laws  of  earth- 
quakes furnishes  various  means  of  preventing  their  ca- 
lamitous effects,  by  giving  intimations  of  their  future  ac- 
tion. The  materials  of  this  extensive  subdivision  are  de- 
rived mostly  from  direct  observations,  made  with  the  aid 
of  various  instruments,  including  the  anemometer,  which 
determines  the  force  and  direction  of  the  winds,  the  hy- 
grometer, the  thermometer,  the  barometer,  the  pluviame- 
ter  or  rain-gauge,  the  tide-gauge,  and  the  seismometer, 
which  measures  the  force  of  earthquake  shocks. 

2.  Chemistry  affords  an  insight  into  the  recondite 
structure  and  operations  of  nature,  by  disclosing  the 
properties  of  its  primary  elements,  and  the  laws  of  their 
combination  and  separation.  It  also  bears  an  important 
relation  to  several  other  sciences,  and  to  many  of  the 
arts.  It  enables  the  Physiologist  to  determine  the  com- 
position of  secretions  and  tissues ;  it  unfolds  to  the  Geol- 
ogist the  composition  of  rocks ;  and  it  gives  the  Botanist 
similar  knowlege  regarding  plants.  It  is  likewise  of 
much  importance  in  establishing  proper  rules  of  dietet- 
ics ;  and  it  contributes  to  the  improvement  of  tillage,  by 
analysing  soils,  and  showing  what  elements  they  possess 
or  lack,  and  how  they  require  to  be  cultivated,  in  order 
to  yield  abundant  produce. 

The  phenomena  of  Chemistry  should  be  distinguished 
from  their  hypothetical  explanations :  the  character  of 
the  latter  does  not  affect  the  truths  of  the  former,  al- 
though their  causes  should  continue  as  unknown  as  the 
cause  of  the  yellow  color  of  gold,  or  the  sweet  taste  of 


372  PHYSICAL  SCIENCES.      [CHAP.  XXIII. 

This  science  is  based  chiefly  on  experiments,  perform- 
ed by  means  of  heat,  electricity,  light,  and  the  mutual 
action  of  substances  on  each  other.  These  experiments 
frequently  require  much  ingenuity  and  manual  dexterity, 
and  a  careful  application  of  the  most  exact  and  reliable 
methods  of  determining  quantity,  with  very  delicate  and 
accurate  instruments.  Many  substances  are  of  a  com- 
plex structure ;  and  it  is  often  no  "easy  task  to  determine 
whether  a  compound,  obtained  from  analysis,  was  not 
formed  during  the  process,  by  a  play  of  the  affinities. 
Another  difficulty  arises  from  the  extremely  small  amount 
of  some  constituent  element,  which  yet  greatly  affects 
the  character  of  the  compound. 

3.  Mineralogy  is  interesting  on  account  of  its  applica- 
tions in  mining,  metallurgy,  and  the  construction  of  op- 
tical instruments.     It  also  exhibits  the  beauty  and  regu- 
larity of  inorganic  nature,  in  a  peculiar  manner,  as  every 
compound   exhibits  a   characteristic  geometrical  form. 
This  enables  the  mineralogist  to  determine  the  character 
of  a  mineral  very  easily,  where  a  person  ignorant  of  the 
science  would  be  readily  misled  or  deceived.     He  is  in 
no  danger  of  paying  the  price  of  a  diamond  for  a  piece 
of  quartz  crystal,  of  comparatively  no  value. 

The  composition  of  minerals  is  determined  by  chem- 
ical analysis ;  and  the  exact  form  of  crystals  may  be  as- 
certained by  the  goniometer,  while  Geology  and  Geog- 
raphy aid  us  in  ascertaining  wrhere  the  various  substances" 
may  be  found. 

4.  From  shapeless  masses  of  rocks  and  dirt,  and  the 
broken,  and  frequently  petrified,  organic  remains  imbed- 
ded in  them,  Geology  unfolds  the  history  of  the  Earth, 
and  the  numerous  Avonders  which  it  exhibits.     The  ori- 
gin of  seas  and  oceans,  of  the  lofty  mountains  and  the 
lowly  vales,  with  their  endless  diversities,  forms  a  sub- 
ject in  which  all  intelligent  minds  must  feel  much  inter- 
est ;  and  this  is  increased  when  we  discover  the  agencies 
by  which  they  were  produced,  and  the  organisms  by 
which  the  Earth  was  formerly  tenanted. 

This  science  is  also  very  important  in  an  economical 
point  of  view.  It  teaches  us  where  to  look  for  metallic 
ores,  coal,  building  and  earthenware  materials,  subterra- 
neous supplies  of  water,  mineral  manures,  the  precious 
metals,  and  gems.  Much  money  and  labor  have  been 
lost  in  searching  and  digging  for  such  things,  where 


SEC.  5.]  GEOGRAPHICAL  SCIENCES.  373 

Geology  would  inform  us  that  they  were  not  to  be  found, 
while  they  have  lain  hid,  for  many  ages,  in  favorable  sit- 
uations, where  it  would  have  readily  disclosed  their  ex- 
istence. It  also  assists  us  in  determining  the  character 
and  capabilities  of  soils,  while  the  palaeontological  por- 
tion throws  light  on  several  difficulties  in  the  organical 
sciences. 

The  position,  structure,  and  size  of  rocks,  and  of  the 
organic  remains  found  in  them,  are  ascertained  from  in- 
pecting  the  face  of  the  country  in  different  regions,  and 
the  sections  laid  bare  by  flowing  water,  subterraneous 
agencies,  or  works  of  art.  The  investigation  is  much 
facilitated  by  the  edges  of  the  rocks  having  been  very 
frequently  exposed  to  view,  along  the  surface  of  the 
ground,  because  they  were  tilted  up  from  their  first  po- 
sition, either  by  the  parts  beneath  giving  way  or  by  an 
upheaving  force  having  been  applied  from  below.  The 
dip  and  strike  of  rocks  are  most  easily  measured  with 
the  compass  and  the  clinometer,  which  is  a  simple  mod- 
ification of  the  quadrant  of  altitude.  Then,  by  measur- 
ing the  horizontal  thickness,  at  right  angles  to  the  strike, 
the  real  thickness  is  found  by  simply  solving  a  right- 
angled  triangle.  The  nature  of  the  forces  which  pro- 
duced the  phenomena,  and  of  the  organic  remains  found 
in  the  rocks,  is  ascertained  by  calling  in  the  aid  of  Mathe- 
matics, and  the  other  physical  sciences,  as  may  be  requi- 
site. 

There  is  thus  furnished  a  wide  field  for  inferences,  re- 
garding the  circumstances  under  which  those  phenomena 
originated,  and  the  actual  condition  of  the  Earth,  during 
the  various  periods.  The  supposition  that  the  Creator 
employed  an  endless  series  of  miracles,  in  order  to  entrap 
us  into  false  inferences,  is  manifestly  absurd  ;  and,  there- 
fore, geological  phenomena  are  to  be  attributed  to  those 
agencies  which  are  known  to  produce  similar  appear- 
ances at  present,  so  far  as  these  are  adequate.  When 
they  are  not,  recourse  must  be  had  to  the  usual  modes 
of  ascertaining  causes,  in  similar  cases. (27) 


374  MENTAL  SCIENCES.       [CHAP.  XXIV. 


CHAPTER  XXIV. 

OF   THE   MENTAL   SCIENCES. 

§  1.  OF  THE  MENTAL  SCIENCES  IN  GENERAL. — General  Character  of 
this  Class. — Causes  of  their  comparatively  slow  Progress. — Their 
principal  Foundations,  and  Importance. — Why  frequently  under- 
valued.— Directions  for  Study. 

THE  mental  sciences  exhibit  a  wide  range  of  primary 
facts,  consisting  partly  of  necessary  and  partly  of  contin- 
gent truths,  while  they  abound  with  inferences.  Many 
of  their  propositions  are  known  by  direct  discernment, 
while  others  are  established  by  an  analysis  of  thought 
and  motives,  a  process  which  is  never  employed  in  other 
sciences.  Owing  to  the  extreme  rapidity  of  thought,  to 
our  performing  several  mental  operations  simultaneously, 
and  to  one  thought's  readily  leading  to  another,  this  anal- 
ysis is  generally  attended  with  difficulty ;  and  it  is  fre- 
quently necessary  to  have  recourse  to  indirect  means  of 
effecting  our  object.  Mere  external  observation  is  of  lit- 
tle avail,  in  surmounting  the  chief  difficulties.  If  to  this 
we  add  that,  owing  to  the  manifest  bearings  of  the  points 
in  question  on  our  future  condition,  strong  prejudices  fre- 
quently interfere,  we  can  easily  understand  why  these 
sciences  have  made  such  slow  progress,  compared  with 
some  others. 

The  principal  foundations  of  the  mental  sciences  are, 
immediate  discernments,  the  conclusions  of  the  physical 
sciences,  and  inductions  from  History  or  Biography. 
They  are  of  the  utmost  importance,  since  they  influence 
our  condition  much  more  extensively  than  any  other  di- 
vision of  knowledge,  and  their  principles  are  requisite  to 
regulate  our  daily  thoughts  and  conduct.  They  also 
greatly  influence  the  condition  of  all  other  branches  of 
knowledge.  For  the  mind  must  receive  that  thorough 
discipline  and  those  external  advantages  which  only  the 
proper  study  and  general  diffusion  of  these  sciences  can 
give,  before  it  is  in  a  condition  to  enlarge  and  improve 
to  the  utmost  the  other  fields  of  human  investigation,  or 
apply  them  to  their  true  objects. 


SEC.  1.]  USES  AND  STUDY.  375 

The  various  departments  of  knowledge  are  so  connect- 
ed that  an  improvement  in  one  favors  a  corresponding 
advance  in  others ;  and  this  is  especially  the  case  with 
that  now  under  consideration,  on  account  of  its  extensive 
influence  in  improving  the  mind,  removing  restraints  on 
proper  investigation,  and  furnishing  the  various  other 
requisites  to  success.  It  teaches  mankind  the  true  value 
of  knowledge,  and  at  the  same  time  disposes  them  to 
furnish  the  means  for  its  successful  cultivation,  and  points 
out  how  this  object  is  to  be  secured.  They  also  inure 
us  to  those  habits  of  close  attention  to  mental  phenome- 
na and  recondite,  but  important,  distinctions,  which  are 
requisite  to  a  proper  solution  of  many  practical  problems 
of  the  utmost  moment. 

These  sciences  also  teach  us  the  difficulties  attending 
many  of  their  applications,  and  thus  obviate  the  dogma- 
tism into  which  those  are  incessantly  falling  who  are  ig- 
norant of  these  difficulties.  A  man  totally  ignorant  of  a 
mechanical  art  is  apt  to  speak  hesitatingly  and  distrust- 
fully regarding  it,  whereas  those  who  are  equally  ignorant 
of  the  mental  sciences,  are  apt  to  speak  very  confidently 
regarding  points  which  require  for  their  solution  an  ex- 
tensive knowledge  and  careful  application  of  their  prin- 
ciples ;  and  thus  they  often  utter  gross  absurdities,  with- 
out ever  suspecting  the  error. 

The  mental  sciences  treat  of  subjects  which  do  not 
immediately  affect  the  senses  like  those  of  Physics,  and 
they  are  founded,  in  a  great  measure,  on  truths  or  phe- 
nomena familiar  to  all,  whence  we  are  apt  to  think  that 
we  know  them  sufficiently  without  study,  or  that  they 
are  of  little  consequence.  Yet  they  require  diligent 
study,  in  order  to  be  well  understood,  while  our  views 
of  their  subjects  mold  our  whole  character,  and  conse- 
quently determine  our  general  conduct  through  life,  and 
our  whole  future  condition,  so  that,  if  these  views  should 
be  radically  erroneous,  correct  and  extensive  knowledge 
on  other  subjects  will  only  render  a  person  more  power- 
ful for  evil,  both  to  himself  and  to  others. 

In  studying  the  mental  sciences,  we  should  beware  of 
adopting  alleged  or  supposed,  in  place  of  real,  intuitions 
or  inductions,  and  guard  particularly  against  fallacious 
reasoning,  masked  by  ambiguous  or  obscure  language. 
For  this  purpose,  great  attention  should  be  given  to  the 
principal  terms,  which  cannot  frequently  be  rightly  un- 


376  MENTAL  SCIENCES.       [CHAP.  XXIV. 

derstood  without  closely  considering  our  own  thoughts, 
and  comparing  them  with  the  definitions,  because  the 
subjects  are  not  palpable  to  our  senses,  and  therefore  ob- 
scurity and  vagueness  of  style  are  more  apt  to  occur,  and 
escape  notice,  than  in  other  sciences. 

The  student  should  not  only  test  the  accuracy  of  the 
definitions,  the  credibility  of  the  evidences,  and  the  sound- 
ness of  the  reasoning,  but  he  should  carefully  examine 
whether  statements  alleged  to  be  truths  of  consciousness 
are  so  in  reality.  This  is  rendered  the  more  requisite  by 
the  fact  that  direct  discernment  is  very  frequently  ap- 
pealed to  in  every  part  of  these  sciences,  while  the  state- 
ments cannot  be  rightly  tested  by  any  other  means,  as 
external  observation  or  the  testimony  of  others  is  of  no 
avail. 

There  is  here  little  danger  of  misspending  time  in 
studying  truths  of  no  practical  importance,  as  very  few 
of  the  cognitions  are  of  that  kind  :  but  we  must  particu- 
larly guard  against  adopting  mere  hypotheses  or  opinions 
as  cognitions,  because  the  former  frequently  usurp  the 
place  of  the  latter.  We  should  also  fix  all  the  leading 
truths  of  these  sciences  distinctly  and  permanently  in  the 
memory,  as  otherwise  they  will  be  generally  misapplied, 
overlooked  or  forgotten,  and  thus  fail  to  secure  their 
principal  objects. 

§  2.  OP  LOGIC  AND  PSYCHOLOGY. — Boundary  between  these  Sci- 
ences.— Importance  of  the  latter. — How  distinguished  from  Physi- 
ology.— Why  not  appreciated  by  many — Modes  in  which  its  Con- 
clusions are  established. — Directions  for  Study. 

Logic  is  confined  to  the  intellect,  and  it  treats  of  their 
products  and  objects  rather  than  of  the  faculties.  Hence 
it  excludes  some  of  the  most  interesting  departments  of 
Psychology,  while  it  discusses  various  subjects  quite  for- 
eign to  that  science.  The  one  treats  of  knowledge,  and 
the  other,  of  the  mind  and  its  faculties  and  susceptibili- 
ties.(28) 

Psychology  is  a  most  important  science,,  because  a 
knowledge  of  the  powers,  affections  and  laws  of  the  mind 
is  requisite  to  our  forming  accurate  conceptions  of  our 
present  duties  and  future  destination,  to  determine  what 
we  ought  to  do,  in  many  momentous  cases,  and  to  use 
our  faculties  aright,  in  our  ordinary  conduct.  It  dis- 
cusses the  physical  organs  only  so  far  as  they  regard 


SEC.  3.]  PSYCHOLOGY.  377 

mental  manifestations,  while  Physiology,  on  the  other 
hand,  views  the  latter  only  as  they  influence  the  former. 

As  several  of  the  truths  of  Psychology  are  made  known 
to  us  by  immediate  consciousness,  many  fail  to  see  the 
advantages  of  studying  it  systematically  ;  and  when  they 
do  so,  they  are  apt  to  fall  into  the  error  of  thinking  that 
they  could  not  fail  to  discern,  whenever  it  might  be  re- 
quired, every  truth  which  they  see  to  be  self-evident  as 
soon  as  it  is  clearly  and  accurately  set  before  them,  al- 
though History  and  Biography  show  the  reverse.  A 
proper  study  of  this  science  is  requisite,  in  order  to  un- 
derstand the  laws  and  processes  of  the  mind,  and  to  avoid 
the  grave  errors  into  which  we  are  very  liable  to  fall 
when  we  adopt  as  truths  conclusions  formed  without  any 
careful  consideration  of  the  subject.  The  maxim  that 
first  impressions  are  not  reliable,  holds  true  of  mental,  as 
well  as  of  physical,  objects. 

Psychology  appeals  to  our  individual  consciousness,  at 
every  step,  except  where  it  introduces  other  unexcep- 
tionable evidence :  and  it  possesses  the  great  advantage 
of  being  based  chiefly  on  immediate  discernments,  from 
which  inferences  are  deduced  as  in  all  other  sciences. 

In  studying  this  important  science,  we  must  beware 
of  obscure  language  and  dogmatic  statements  requiring 
proof,  which  is  not  given.  Particular  attention  should 
be  paid  to  the  precise  signification  of  terms,  as  there  is 
no  subject  on  which  we  are  more  liable  to  be  misled  by 
considering  mere  expressions,  and  overlooking  what  they 
denote. 

§  3.  OF  THEOLOGY. — Sublimity  and  Importance  of  this  Science. — 
How  the  chief  Conclusions  of  Natural  Theology  are  established. — 
Its  Uses  and  Study. — Biblical  Theology. — Its  Evidences. — Inquiry 
regarding  its  Records,  and  their  Purity. — Its  Relation  to  the  other 
Division. — Observations  on  Study. — Scripture  Interpretation. — In- 
fluence of  Prejudices. — Two  Extremes. — Proper  Course. 

In  the  sublimity  of  its  subject,  Theology  occupies  a 
much  higher  position  than  any  other  science.  Although 
the  subjects  of  Astronomy  are  so  vast  as  to  transcend 
the  powers  of  adequate  conception,  yet  they  are  only 
masses  of  inanimate  matter,  inane  as  the  empty  void. 
Theology,  on  the  contrary,  investigates  the  existence  and 
character  of  the  Eternal  Ruler,  who  formed  and  governs 
all :  and  the  light  which  they  throw  on  his  attributes, 


378  MEXTAL  SCIENCES.       [CiiAP.  XXIV. 

constitutes  the  greatest  value  of  Astronomy,  and  all  the 
other  physical  sciences. 

The  importance  of  Theology  is  not  inferior  to  its  sub- 
limity. A  knowledge  of  God's  character  fornis  the  found- 
ation of  all  true  religion,  which  is  necessary  to  save  man- 
kind from  the  horrors  of  superstition  and  practical  athe- 
ism, and  our  views  of  which  determine  our  condition 
through  eternity,  compared  with  which  the  longest  life 
shrinks  to  nothing.  Religion  affords  consolation  when 
nothing  else  can  ;  and  it  is  the  only  thing  that  furnishes 
enjoyments  which  will  never  fade  nor  cloy.  It  also  leads 
to  the  performance  of  many  important  duties  which  no 
other  motive  will  secure,  so  that  it  is  as  indispensable  to 
steady  good  conduct  as  it  is  to  permanent  happiness. 

Our  views  of  the  Most  High  sway  the  whole  circle  of 
our  thoughts  and  actions.  For,  when  a  man  learns  and 
bears  in  mind  the  true  character  of  the  Eternal,  his  own 
is  gradually  improved  and  elevated,  by  being  assimilated 
to  the  object  of  his  constant  affection,  admiration  and 
reverence,  while  he  who  continues  ignorant  and  regard- 
less of  this  subject,  generally  becomes  the  slave  of  appe- 
tite, debasing  desires  or  malignant  and  selfish  feelings, 
and  proceeds  from  bad  to  worse.  Hence  the  existence 
and  character  of  God,  and  the  relation  in  which  we 
stand  to  him,  as  accountable,  guilty  and  immortal  beings, 
are  matters  to  which  every  one  should  devote  a  very 
careful,  diligent  and  impartial  examination,  and  on  which 
we  should  particularly  beware  of  assuming  that  anything 
is  either  true  or  false,  without  conclusive  proof. 

The  existence  of  the  Deity  forms  the  first  object  of  at- 
tention, in  Natural  Theology.  It  is  proved  by  the  phe- 
nomena of  nature,  both  animate  and  inanimate,  since  ev- 
ery supposition  which  attempts  to  account  for  these, 
without  a  forming  and  presiding  Intelligence,  involves 
demonstrable  impossibilities.  The  character  of  God  is 
proved  by  the  endless  displays  of  incomprehensible  skill, 
power  and  benevolence,  which  are  manifested  through- 
out the  whole  creation. 

Natural  Theology  strengthens  the  foundations  of  re- 
ligion and  morality,  while  it  furnishes  much  exalted  en- 
joyment, by  giving  us  correct  views  of  the  works  of  the 
Creator,  and  thus  enabling  us  to  participate  in  his  joys, 
to  the  extent  of  our  comparatively  limited  capacities.  A 
knowledge  of  its  principles  also  furnishes  important  aid 


SEC.  3.]  THEOLOGY.  379 

in  rightly  interpreting  the  language  of  Revelation,  which 
assumes  these  principles  as' known,  or  at  least  knowable, 
independently  of  its  own  teachings. 

The  elements  of  this  division  may  first  be  learned  from 
books,  after  which  we  may  continually  enlarge  our  knowl- 
edge of  it,  by  observing  nature,  both  rational  and  irra- 
tional, with  the  aid  of  the  principles  previously  acquired. 

In  Biblical  Theology,  the  evidences  of  Revelation  form 
the  first  subject  of  consideration.  They  lie  in  the  nature 
of  the  truths  revealed,  and  in  historical  narratives  which 
are  tested  by  the  ordinary  criterions.  We  are  then  to 
inquire  what  are  the  genuine  records  of  Revelation,  in 
order  that  we  may  distinguish  them  from  spurious  com- 
positions, which  falsely  claim  to  form  a  part  of  them. 
We  should  also  examine  the  purity  of  the  text  of  those 
records,  by  means  of  the  rules  regarding  written  testi- 
mony, and  also  ascertain  the  precise  limits  of  Revelation. 

After  disposing  of  those  preliminary  matters,  we  are 
to  examine  what  Revelation  declares.  It  is,  of  course, 
consistent  with  the  conclusions  of  Natural  Theology:  but 
it  goes  much  farther,  and  teaches  us  various  things  on 
which  Natural  Theology  sheds  no  clear  light. 

The  doctrines  of  Revelation  exert  a  peculiar  elevating 
and  purifying  influence  on  those  -who  really  understand 
and  believe  them,  owing  both  to  the  impressiveness  of 
direct  communications  from  the  Supreme  Being,  and 
their  thoroughly  reformatory  and  exalting  character. 
They  fail  to  produce  such  effects  only  upon  those  whose 
reception  of  them  is  merely  nominal,  or  who  modify  and 
corrupt  them,  to  suit  their  evil  wishes.  The  teachings 
of  Natural  Theology  are  not  sufficiently  authoritative 
and  powerful  to  produce,  by  themselves,  those  changes 
in  the  conduct  and  feelings  of  mankind  which  are  essen- 
tial to  their  permanent  welfare. 

As  the  whole  of  revealed  religion  is  contained  in  the 
Sacred  Scriptures,  they  should  form  the  principal  subject 
of  our  study  of  this  division  of  the  science.  The  charac- 
teristic benevolence  of  the  Most  High  is  shown  in  their 
being  well  adapted  to  the  comprehension  of  every  class 
of  sane  minds :  and  although  some  parts  are  obscure  to 
the  unlearned,  these  form  but  a  small  portion  of  the  whole. 
All  the  principal  doctrines  are  expressed  and  illustrated 
so  clearly  and  variously,  that  no  diligent  student,  who  is 
desirous  of  knowing  the  truth,  need  misunderstand  them. 


380  MENTAL  SCIENCES.       [CHAP.  XXIY. 

Much  assistance  may  be  derived  from  various  other 
works,  if  judiciously  used:  but,  whenever  we  have  re- 
course to  them,  we  should  beware  of  fallacies  of  testi- 
mony, misinterpretation  of  language,  and  appeals  to  au- 
thority. We  should  never  forget  that  Scripture  is  its 
own  best  interpreter,  and  that  many  works  which  pro- 
fess to  unfold  the  doctrines  of  Revelation,  teach  most 
pernicious  errors.  These  we  may  avoid  by  a  careful  and 
continued  study  of  the  Scriptures,  which  contain  the  only 
infallible  authority  on  this  subject,  and  on  a  right  under- 
standing and  belief  of  whose  principal  doctrines  depends 
our  eternal  all.  We  should  also  bear  in  mind  that  one 
fundamental  error  may  mislead  us  fatally  regarding  the 
whole  subject,  because  the  essential  doctrines  are  so  con- 
nected and  dependent  that  we  cannot  have  right  views 
of  some  if  we  are  radically  mistaken  regarding  others. 

The  Bible  is  interpreted  by  the  ordinary  rules  of  in- 
terpretation, since  we  are  evidently  addressed  in  the  or- 
dinary language  of  mankind,  which  we  can  best  under- 
stand, and  neither  in  that  of  mathematicians  nor  of  en- 
thusiasts. The  style  is  often  figurative  or  poetical :  but 
the  figures  are  such  as  occur  in  all  impassioned  discourse, 
and  are  employed  with  great  uniformity.  Consequently 
the  language  is  generally  more  intelligible  than  if  it  had 
been  more  literal,  because,  in  the  long  lapse  of  time,  the 
latter  would  have  changed  more,  while  its  variations 
would  have  been  less  obvious.  The  occult  senses,  pro- 
fessed to  be  found  in  the  Scriptures  by  the  Cabalists 
and  other  mystics,  are  only  the  dreams  of  imbecile  un- 
derstandings. 

Throughout  our  study  of  this  most  important  subject, 
we  require  to  guard  carefully  against  the  influence  of 
prejudices,  as  there  is  none  on  which  they  are  more  apt 
to  mislead  us.  These  are  the  main  causes  of  the  great 
diversity  of  religious  belief  that  has  hitherto  prevailed 
among  mankind,  and  not  the  inherent  difficulties  of  the 
subject,  which  is  by  no  means  the  most  abstruse  or  dif- 
ficult branch  of  human  investigation. 

On  the  one  hand,  multitudes  have  adopted  supersti- 
tious and  demoralizing  doctrines,  because  they  form  part 
of  the  parental  creed,  and  offer  an  easy  and  grateful  road 
to  future  bliss.  On  the  other  hand,  many  have  been  led 
by  such  doctrines,  and  the  corresponding  practices  of 
their  votaries,  to  discard  all  revealed  religion  as  a  delu- 


SEC.  4.]  MORALITY.  381 

sion  or  imposture,  because  they  do  not  care  to  search 
into  the  real  state  of  matters,  or  to  see  themselves  as 
they  actually  are.  Both  classes  are  alike  in  desiring  to 
shun  the  labor  of  proper  investigation,  and  the  sacrifices 
which  a  knowledge  of  the  truth  might  impose.  Hence, 
the  former  believe  without  any  satisfactory  evidence,  and 
the  latter  reject  conclusive  proofs  without  an  impartial 
examination. 

Nature  and  Revelation  are  evidently  the  only  reliable 
sources  of  religious  knowledge:  and,  therefore,  whatever 
is  inconsistent  with  their  teachings,  or  not  legitimately 
proved  from  either,  should  be  rejected.  But,  before  re- 
jecting any  doctrine,  we  ought  to  know  that  it  belongs 
to  this  class.  On  the  other  hand,  whatever  is  proved  by 
either,  should  be  firmly  and  unhesitatingly  believed. 

§  4.  Or  MORALITY,  on  ETHICAL  SCIENCE. — Subjects  and  Founda- 
tions of  Morality. — What  it  aims  at  effecting. — Its  Advantages. — 
Directions  for  Study. 

This  science  first  inquires  into  the  nature  and  founda- 
tions of  duty  in  general,  and  afterwards  discusses  the  va- 
rious kinds  of  duty  specially.  It  derives  its  principal 
primary  premises  from  Psychology,  Theology,  and  Phys- 
ics, although  it  also  employs  various  truths  derived  from 
other  sources. 

To  determine  beforehand  the  duty  of  a  person,  in  ev- 
ery combination  of  circumstances  that  can  arise,  is  im- 
practicable, since  these  are  endlessly  diversified.  But 
we  may  establish  principles,  which  apply  to  all  cases, 
and  discuss  their  chief  applications,  so  that  the  precise 
line  of  conduct  which  duty  requires,  may  be  distinctly 
laid  down,  in  all  important  cases  of  frequent  occurrence. 
When  once  we  clearly  understand  both  a  principle  and 
its  leading  applications,  we  can  generally,  without  diffi- 
culty or  inconvenience,  determine  its  other  applications, 
since  they  are  always  very  similar  to  those  already 
known. 

The  belief  that  the  mind  comprehends  the  nature  of 
right  and  wrong,  as  the  eye  perceives  the  distinctions  of 
color,  is  refuted  by  the  diversities  of  opinion  which  have 
prevailed  among  mankind  on  many  moral  questions. 
Were  that  belief  correct,  there  could  be  no  more  differ- 
ence of  opinion  as  to  whether  a  certain  course  is  right, 
than  there  is  about  the  color  of  the  sky  or  the  taste  of 


382  MENTAL  SCIENCES.       [CHAP.  XXIV. 

sugar.  On  the  contrary,  what  is  right  and  wrong  can- 
not frequently  be  determined  without  a  proper  applica- 
tion of  moral  principles,  which  are  established  only  by  a 
close  investigation  of  several  subjects  by  no  means  free 
from  difficulty. 

The  Holy  Scriptures  are  designed  to  aid,  and  not 
to  supersede,  the  use  of  our  faculties ;  and,  therefore, 
they  leave  many  important  questions  to  be  answered  by 
our  own  investigations.  Thus,  we  are  commanded  to  do 
to  others  as  we  would  have  them  do  to  us :  but  we  are 
not  told  whether  our  actual  or  our  reasonable  wishes 
are  the  test.  We  can  solve  such  questions  readily  with- 
out the  aid  of  Revelation  ;  and  it  is  evidently  no  part  of 
the  plan  of  Providence  to  encourage  indolence,  and  fos- 
ter mental  imbecility,  by  solving  for  us  problems  which 
we  can  easily  solve  for  ourselves,  by  a  proper  application 
of  our  faculties. 

Morality  discusses  the  whole  subject  of  duty,  once  for 
all,  and  thus  guards  us  against  the  various  dangers  inci- 
dent to  sitting  down  to  solve  moral  problems,  when  we 
ought  to  be  acting.  A  man  who  has  never  considered 
what  his  duties  are,  until  he  is  placed  amidst  the  circum- 
stances in  which  he  is  required  to  act,  is  very  apt  to  con- 
vince himself  that  what  he  is  strongly  tempted  to  do,  is 
right,  whereas,  if  he  had  previously  examined  the  sub- 
ject, while  he  was  free  from  any  such  excitement,  he 
would  see  it  in  its  true  light,  and  the  settled  view,  thus 
obtained,  would  enable  him  to  resist  the  temptation,  and 
to  act  as  duty  dictated.  Unprincipled  or  immoral  con- 
duct is  caused,  in  no  small  degree,  by  failing  to  consider 
Avhat  duty  requires,  till  the  time  for  action  comes,  in  con- 
sequence of  which  the  passion  or  appetite  of  the  moment 
controls  the  conduct. 

The  influence  of  prejudices  is  never  more  powerful  than 
when  we  examine  what  duty  requires,  with  reference  to 
objects  of  strong  desire,  while  these  are  placed  in  full 
view.  For  we  inevitably  see  distinctly  the  sacrifice  that 
must  be  made,  in  the  event  of  our  conclusions  being  hos- 
tile to  the  gratification  of  the  desire.  Hence  the  great 
advantage  of  ascertaining  what  our  duties  are,  before 
such  desires  have  been  thus  excited,  as  their  influence  is 
thus  rendered  comparatively  feeble. 

In  studying  Morality,  the  learner  should  first  obtain 
clear  and  accurate  conceptions  of  the  nature  and  sane- 


SEC.  5.]  JURISPRUDENCE.  383 

tions  of  duty  in  general,  and  afterwards  investigate  the 
fixed  and  certain  relations  which  the  various  classes  of 
duties  bear  to  his  present  and  future  condition.  In  or- 
der that  this  science  should  produce  its  legitimate  effects, 
it  is  not  enough  to  read  or  hear  that  we  should  do  this 
and  not  do  that :  we  must  clearly  see  the  sure  and  inev- 
itable consequences  of  so  doing,  and  then  fix  them  dis- 
tinctly and  permanently  in  the  memory. 

§  a.  OF  JURISPRUDENCE. — Nature,  Foundations,  and  Uses,  of  this 
Science. — How  related  to  Legislation. — Practical  Application. — 
Importance  of  discussing  Principles  in  the  abstract. — Study. 

Jurisprudence  resembles  Morality  in  its  processes :  but 
it  considers  man  only  as  the  subject  of  political  govern- 
ment ;  and,  therefore,  it  is  much  narrower  in  its  range. 
From  premises  obtained  chiefly  from  Psychology,  Moral- 
ity and  History,  it  deduces  the  laws  best  adapted  to  man, 
in  a  normal  state,  or  that  condition  in  which  the  commu- 
nity are  enlightened,  and  attentive  to  everything  that  se- 
riously concerns  them,  whether  present  or  future. 

A  knowledge  of  this  science  is  requisite  in  order  to 
understand  the  true  functions,  influence,  and  powers,  oi" 
government,  regarding  which  many  have  formed  very 
erroneous  views.  On  the  one  hand,  calamities  have  been 
attributed  to  misgovernment,  which  were  wholly  owing 
to  other  causes,  while  things  have  been  expected  from  a 
good  government  which  the  best  cannot  confer.  Mis- 
government  is  itself  an  effect  of  evils  which  previously 
existed  ;  and  these  may  continue  to  exist  under  any  gov- 
ernment, as  their  removal  requires  more  potent  agencies 
than  human  laws.  On  the  other  hand,  the  sufferings  pro- 
duced by  bad  lawrs,  or  the  abuses  of  power,  have  often 
been  wickedly  laid  to  the  charge  of  Providence. 

It  is  necessary  to  understand  the  elements  of  Juris- 
prudence, in  order  to  form  correct  opinions  regarding 
the  nature  of  true  liberty  and  individual  rights :  and  a 
citizen  cannot  secure  his  own  rights,  or  perform  his  duty 
to  his  country,  unless  he  knows  what  the  former  are,  and 
what  measures  the  public  welfare  requires. 

Jurisprudence  in  the  mental  sciences  resembles  Hygi- 
ene in  the  physical.  The  Hygienist  deduces  the  laws  of 
health  from  a  knowledge  of  the  human  organization  and 
the  nature  of  the  agents  that  affect  it :  his  conclusions 
are  not  in  the  least  invalidated  by  the  fact  that  many  arc 


384  MENTAL  SCIENCES.       [CHAP.  XXIV. 

ignorant  of  those  laws,  that  several  are  too  much  under 
the  influence  of  bad  habits  to  obey  them  perfectly,  even 
after  they  have  been  clearly  set  before  them,  and  that 
others  have  contracted  diseases  which  render  medical 
treatment  desirable.  So  the  jurist  deduces  the  principles 
of  his  science  from  a  knowledge  of  the  mental  character- 
istics of  man,  and  the  agencies  by  which  they  are  affect- 
ed. Many,  or  possibly  most,  nations  may  be  too  igno- 
rant, prejudiced,  or  oppressed,  to  adopt  those  principles 
to  any  great  extent.  Yet  much  is  effected  by  clearly  es- 
tablishing them :  for  when  a  people  who  possess  any  con- 
trol over  their  laws  and  government,  see  clearly  what 
duty  and  their  true  interests  demand,  they  will  take  some 
steps  in  the  right  direction,  and  these  will  prepare  the 
way  for  more,  until  at  length  their  institutions  will  be- 
come conformed  to  the  principles  of  Jurisprudence,  al- 
though such  a  consummation  may  require  many  genera- 
tions. 

The  duties  of  the  legislator  differ  from  those  of  the 
jurist.  It  is  the  duty  of  the  former  to  propose  only  such 
changes  as  the  nation  are  likely  to  sustain  and  carry  out 
in  practice:  for,  if  he  were  to  go  farther,  the  innovations 
would  be  only  a  dead  letter.  Every  step  in  the  right 
direction,  however,  is  a  gain,  provided  it  be  real,  and 
there  be  no  subsequent  retrogradation.  The  jurist,  on 
the  other  hand,  aims  at  establishing  scientific  principles, 
applicable  in  every  age  and  country,  independently  of 
any  particular  changes  or  circumstances. 

When  a  law  is  found  to  be  defective,  an  application  of 
the  previously  established  principles  of  this  science  to 
the  circumstances  of  the  case,  indicates  the  change  which 
ought  to  be  made :  and,  without  such  guidance,  changes 
would  be  as  likely  to  deteriorate  as  to  improve :  for  they 
would  either  be  made  at  haphazard  or  under  the  influ- 
ence of  strong  prejudices,  excited  by  discussing  juridical 
principles  for  the  first  time,  in  connection  with  the  con- 
templated changes,  and  the  numerous  real  or  supposed 
interests  which  they  involved.  But  when  those  princi- 
ples are  first  established  and  understood,  without  any  ref- 
erence to  party  questions  or  passing  events,  the  changes 
which  ought  to  be  made,  may  be  ascertained  without 
any  extraordinary  difficulty,  since  all  parties  then  stand 
on  the  ground  of  established  principles,  so  that  prejudices 
are  allayed,  and  the  means  furnished  for  rightly  determ- 
ining the  matter  in  question. 


SEC.  1.]  PHILOLOGY.  385 

Before  commencing  the  study  of  this  science,  the 
learner  should  master  the  principles  of  Morality,  without 
a  knowledge  of  which  Jurisprudence  cannot  be  studied 
with  success.  He  should  then  acquire  correct  views  of 
the  foundations,  legitimate  functions,  and  proper  limits 
of  government  and  law :  and  he  should  always  distin- 
guish the  existing  laws  from  the  principles  of  this  sci- 
ence, with  which  they  have  often  been  confounded.  He 
should  also  distinguish  Jurisprudence  from  Morality : 
for,  although  the  two  are  closely  connected,  they  are  by 
no  means  identical.  Our  duty  to  others  often  requires 
from  us  much  more  than  human  laws  can  prudently  de- 
mand, and  much  less  enforce,  while  these  laws  take  no 
cognizance  of  the  still  more  extensive  and  important  class 
of  "duties  with  which  others  have  no  direct  concern.(29) 


CHAPTER  XXV. 

OF   MIXED   KNOWLEDGE. 

§  1.  OF  PHILOLOGY. — Two  modes  of  learning  a  Language. — Ultimate 
Sources  of  Knowledge  regarding  dead  Languages. —  Grammars 
and  Dictionaries. — Usages. — Authorities. — Branches  subsidiary  to 
Philology. — Etymologies. — Requisites  to  knowing  a  Language. — 
How  best  attained. — Various  Significations  of  Words. — Common 
Error. — Conversation  and  Composition. — Comparative  Philology. 
— Its  leading  Principles  and  Results. — Affinities  of  Languages. — 
General  Philology. — Uses  of  Philology. 

A  LANGUAGE  may  be  learned  either  by  simply  observ- 
ing spoken  usage,  or  by  means  of  special  instructions 
from  others,  in  a  language  which  we  already  understand. 
The  elements  of  the  vernacular  are  necessarily  learned 
by  the  former  method,  in  the  manner  already  pointed 
out ;  and  the  youth  can  afterwards  learn,  from  direct  in- 
quiries, the  exact  significations  of  the  more  abstruse,  rare 
or  vague  terms ;  or  he  may  consult  grammars,  dictiona- 
ries, and  scientific  treatises,  for  that  purpose. 

The  ultimate  sources  of  knowledge  regarding  a  dead 
language  are  chiefly  the  following:  (1)  Living  Lan- 
guages which  resemble  the  dead.  (2)  Translations  made 
into  some  living  or  known  language,  by  persons  who 
learned  the  dead  from  spoken  usage.  (3)  Grammars  or 
dictionaries  written  by  such  persons,  in  some  known  Ian- 


386  MIXED  KNOWLEDGE.       [CHAP.  XXV. 

guage.  (4)  Historical  compositions  which  relate  events 
known  to  us  through  some  other  source.  (5)  A  com- 
parison of  works  of  ancien,t  art  with  the  descriptions  or 
allusions  of  authors.  These  sources  frequently  make 
known  the  significations  of  all  the  more  common  words, 
inflections  and  constructions,  after  which  reading  good 
authors  will  farther  extend  our  knowledge,  since  we  can 
now  learn  the  exact  significations  of  many  words  and 
phrases  from  the  context.  The  learner  might  now  com- 
pose a  grammar  and  dictionary  of  the  language,  and  thus 
greatly  facilitate  and  abridge  the  labors  of  succeeding 
students. 

After  having  obtained  a  good  general  knowledge  of 
the  language,  by  either  or  both  of  those  methods,  we  can 
test  the  correctness  of  grammars  and  dictionaries,  by  an 
appeal  to  the  best  usage,  or  the  practice  of  those  who 
spoke,  or  still  speak,  the  language  in  its  utmost  purity. 
Hence  the  greater  value  of  dictionaries  which  quote  pas- 
sages from  reputable  authors,  since  they  enable  us,  in  a 
great  measure,  to  test  directly  the  accuracy  of  their  own 
definitions. 

In  consulting  such  dictionaries,  we  should  observe  the 
age  and  character  of  the  authors  quoted.  Some  may 
have  written  at  a  time  when  the  language  was  rude  and 
uncultivated,  and  others,  after  it  had  become  corrupted 
and  debased.  Loose  thinking  and  acting  generally  pro- 
duce loose  speaking :  and  hence  a  decline  of  morals  and 
science  is  followed  by  corresponding  deteriorations  of 
language.  Some  authors,  again,  are  above,  and  others 
below,  the  average  of  their  age :  and,  therefore,  we  must 
consider  their  particular  characters,  as  well  as  their  age, 
in  order  to  determine  their  value  as  authorities.  The 
lexicographer  should  point  out  all  the  common  significa- 
tions of  terms,  whether  the  usage  be  good  or  bad :  but 
he  ought  to  indicate  the  nature  of  the  usage,  with  respect 
both  to  age  and  character,  especially  where  his  work  is 
designed  to  aid  learners  in  composition :  and  those  dic- 
tionaries in  which  this  is  properly  done,  are  generally 
very  superior  to  others,  on  all  important  points. 

Among  different  reputable  usages,  the  best  is  that 
which  best  answers  the  ends  of  speech  :  but  that  of  per- 
sons who  know  the  language  well,  and  use  it  carefully,  is 
to  be  deemed  good.  In  cases  of  doubt  or  difficulty,  re- 
course should  be  had  to  unexceptionable  authority,  and 


SEC.  1.]  PHILOLOGY.  387 

the  definitions  of  the  dictionary  tested  by  it,  as  far  as 
may  be  requisite.  Wherever  circumstances  excite  any 
suspicion  of  misquotation,  we  should  refer  to  the  origin- 
al passage,  and  the  part  quoted  should  be  compared  with 
the  context. 

We  should  distinguish  between  treatises  written  by 
philologists  who  conversed  long  and  freely  with  those 
by  whom  the  language  was  correctly  spoken,  and  au- 
thors whose  knowledge  of  it  is  derived  wholly  from 
books.  The  former  are  themselves  authorities  :  the  lat- 
ter are  not ;  and  the  credit  due  to  them  depends  wholly 
on  the  character  of  the  books  which  they  have  read,  and 
the  use  which  they  have  made  of  them.  Hence  their 
statements  are  not  entitled  to  be  implicitly  received, 
without  proof,  in  any  case  of  doubt  or  difficulty.  Philo- 
logical treatises  written  by  such  persons  sometimes  con- 
tain various  errors.  Thus,  we  are  told,  in  Greek  Gram- 
mars, that,  besides  the  active  and  the  passive,  there  is  a 
middle  voice,  representing  only  actions  which  the  sub- 
ject of  the  verb  does  to  himself.  But  wben  we  come  to 
examine  the  real  usages  of  the  language,  we  find  that 
every  one  of  the  so  called  middle  forms  is  either  active 
or  passive  in  signification,  and  represents  actions  done 
to  others,  as  well  as  to  the  subject.  Consequently  the 
middle  voice  is  wholly  imaginary. 

The  acquisition  of  a  language  is  facilitated  by  an  ac- 
quaintance with  the  ethnography  and  history  of  the  peo- 
ple who  originally  spoke  it,  without  which  many  idi- 
omatic terms  and  expressions  cannot  be  rightly  under- 
stood. 

The  etymology  of  a  derivative  generally  indicates  its 
signification,  since  most  derivatives  closely  follow  certain 
rules  which  prevail  in  the  language,  so  that  a  knowledge 
of  the  proper  rule  of  derivation,  and  of  the  signification 
of  the  root,  teaches  us  the  signification  of  the  derivative, 
without  reference  to  any  definition.  Thus,  if  we  know 
what  good  and  hunt  signify,  we  do  not  require  to  be  told 
what  goodness  and  hunter  denote.  There  are  numerous 
exceptions,  however,  chiefly  in  nouns,  although  some  oc- 
cur in  other  parts  of  speech  :  and,  consequently,  etymol- 
ogy is  by  no  means  an  infallible  guide. 

To  know  a  language,  we  must  be  acquainted  with  the 
signification  of  its  words  and  phrases,  and  with  their  in- 
flections, constructions  and  collocations.  The  last  three 


388  MIXED  KNOWLEDGE.       [CHAP.  XXV. 

are  best  acquired,  in  the  first  instance,  from  a  good  gram- 
mar, as  any  other  course  would  require  the  labor  of  many 
years.  After  acquiring  the  simple  elements  of  grammar, 
we  should  learn  the  exact  significations  of  all  the  com- 
mon words,  except  those  numerous  derivatives  regard- 
ing whose  import  we  cannot  hesitate  or  err.  These  are 
best  learned  from  a  classified  vocabulary,  accompanied 
Avith  short  and  easy  sentences,  containing  the  words,  in 
various  forms.  We  should  then  master  the  rules  of  com- 
position and  derivation,  after  which  we  shall  know  the 
signification  of  most  of  the  common  words,  as  soon  as 
we  hear  or  see  them.  Words  of  rare  occurrence  need 
not  occupy  our  attention  till  we  meet  with  them  in  dis- 
course. 

In  ascertaining  the  significations  of  such  words  as  oc- 
cur in  various  senses,  we  should  first  find  the  single  pri- 
mary signification  Avhich  every  such  word  bore,  and  then 
learn  the  secondary  or  derived  significations,  and  trace 
the  steps  by  which  they  arose  from  the  former.  This 
will  both  aid  remembrance,  and  prevent  us  from  con- 
founding the  senses.  Very  few  words  have  more  than 
three  or  four  significations  really  different.  But  an  ex- 
pression which  bears  only  one  meaning  in  its  own  lan- 
guage may  require  to  be  rendered  by  several  in  another, 
owing  to  differences  of  idiom;  and  hence  lexicographers 
sometimes  render  it  in  all  these  ways,  without  adverting 
to  the  fact  that  some  of  the  significations  were  purely 
figurative,  and  that  the  language  of  translation  made  dis- 
tinctions which  were  not  made  in  the  original.  Hence  a 
multitude  of  imaginary  significations  are  found  in  old 
dictionaries,  while  the  primary  is  frequently  omitted,  or 
not  distinguished  from  others.  The  best  philological 
works  of  the  present  day  are  distinguished  by  marked 
improvements  in  these  respects. 

After  thus  acquiring  the  elements  of  the  language,  the 
learner  should  carefully  peruse  good  authors  who  wrote 
in  it,  just  as  he  would  read  works  composed  in  his  ver- 
nacular: and,  while  thus  occupied,  he  should  acquaint 
himself  with  those  parts  of  the  grammar  which  he  had 
not  previously  studied.  If  he  were  to  commence  read- 
ing regular  compositions  sooner,  his  progress  would  be 
very  slow  and  tedious,  as  he  would  require  to  be  turning 
incessantly  to  his  dictionary  or  grammar;  and  he  would 
frequently  fail  to  learn  the  true  significations  of  a  word, 


SEC.  1.]  PHILOLOGY.  389 

after  looking  it  up  many  times,  owing  to  his  mind  being 
distracted  by  the  various  renderings  given,  his  attend- 
ing chiefly  to  the  passage  before  him,  and  long  intervals 
elapsing  between  the  references. 

If  the  learner  require  to  write  and  speak  the  language, 
he  should  use  it  extensively  in  composition  and  conver- 
sation :  but  when  he  requires  only  to  read  it  fluently,  he 
need  not  spend  much  time  in  this  way. 

After  acquiring  a  knowledge  of  several  languages,  we 
may  compare  them,  and  note  their  resemblances  and  di- 
versities. 

Two  languages  may  be  found  to  be  similar  in  their 
words,  but  different  in  their  structure,  like  Latin  and 
French.  This  indicates  that  both  have  a  common  origin, 
and  that  one  has  undergone  great  changes,  either  from 
having  been  adopted  by  a  foreign  people,  or  from  exten- 
sive intercourse  or  intermixture  with  another  race.  The 
language  superseded  will  be  indicated  by  the  structure 
or  various  words  and  idioms  which  it  has  communicated 
to  its  successor. 

Where  several  languages  are  very  similar,  both  in 
words  and  structure,  it  is  to  be  inferred  that  they  are  the 
kindred  offspring  of  a  common  parent,  from  which  they 
sprung  at  a  comparatively  recent  period  in  the  annals  of 
mankind.  No  very  definite  line  of  demarcation  separates 
mere  dialects  from  closely  cognate  languages.  The  best 
distinction  appears  to  be,  that  whenever  the  parties  who 
speak  them,  understand  each  other  without  an  inter- 
preter, they  are  to  be  held  only  different  dialects :  other- 
wise they  are  to  be  deemed  different  languages. 

If  various  languages  exhibit  a  close  resemblance  in 
structure,  but  great  diversity  in  their  words,  it  is  to  be 
inferred  that  they  had  a  common  origin,  and  that  they 
have  been  little  affected  by  foreign  intercourse,  but  that 
those  who  speak  them  have  had  little  intercourse  with 
each  other.  A  good  instance  of  this  kind  is  furnished 
by  the  aboriginal  languages  of  America,  which  all  exhibit 
the  same  polysyllabic  and  polysynthetic  structure,  amid 
great  diversities  in  their  vocabularies. 

Where  languages  greatly  differ,  both  in  words  and  in 
structure,  yet  exhibit  points  of  resemblance  which  can- 
not be  attributed  either  to  chance  or  intercourse,  it  is  to 
be  inferred  that  they  have  had  a  common  origin,  but  that 
they  have  either  been  altered  by  foreign  intercourse,  or 


390  MIXED  KNOWLEDGE.       [CiiAr.  XXV. 

that  those  who  speak  them  have  been  long  separated,  or 
that  the  original  language,  and  consequently  those  who 
spoke  it,  were  quite  rude. 

The  following  are  some  of  the  conclusions  deducible 
from  the  application  of  the  preceding  principles. 

(1)  All   the  languages   of  mankind   have   gradually 
sprung,  by  natural  means,  from  a  common  origin,  which 
has  long  disappeared. (30) 

(2)  They  are  divided  into  great  families,  the  members 
of  which  exhibit  much  closer  affinities  with  each  other 
than  with  those  of  any  second  family,  whence  it  is  to  be 
inferred  that  the  various  families  originated  from  a  com- 
mon source,  subsequent  to  the  general  dispersion  of  man- 
kind. 

(3)  The  families  are  often  subdivided  into  groups,  the 
members  of  which  are  marked  by  peculiarly  close  affini- 
ties.    Some  of  these  groups  contain  many,  and  some, 
only  a  few  languages. 

(4)  Some  exhibit  every  appearance  of  having  gradual- 
ly descended  from  the  primitive  source,  by  the  changes 
naturally  incident  to  human  speech,  without  having  ever 
been  much  affected  by  foreign  elements  or  intercourse, 
While  others  have  become  so  extensively  blended  with 
extraneous  words,  and  changed  in  their  structure,  by  for- 
eign influences,  as  to  have  passed  rapidly  into  new  and 
widely  different  languages.     The  former  may  be  termed 
original,  and  the  latter,  composite  languages.     In  the 
case  of  the  latter,  the  elements  of  the  original  language 
continue  to  form  the  basis  or  framework  of  the  resulting 
speech,  although  the  new  materials  may  form  the  larger 
portion  of  the  whole. 

In  order  to  ascertain  the  affinities  of  a  language,  it  is 
unnecessary  to  learn  all  its  anomalies  and  words.  Its 
general  structure  and  inflections,  and  the  nature  of  the 
primitive  words,  determine  its  whole  character. 

After  acquiring  a  knowledge  of  several  languages  be- 
longing to  the  most  dissimilar  families,  we  can  ascertain 
the  principles  and  structure  of  language  in  general.  Sev- 
eral works  on  fins  subject  present  erroneous  views,  as 
their  authors  were  acquainted  only  with  a  few  languages 
of  similar  structure.  Yet  good  works  on  this  subject 
are  of  much  use,  even  to  those  who  understand  only  the 
vernacular.  They  not  only  tend  to  improve  style,  but 
also  facilitate  the  detection  of  several  fallacies  arising 


SEC.  2.]  ETHNOGRAPHY.  391 

from  language.  Although  philologists  take  good  usage 
as  their  guide,  yet  they  react  powerfully  on  that  of  future 
generations :  and  their  labors  do  much,  not  only  to  fix, 
but  also  to  simplify,  language,  and  to  check,  or  even  re- 
move, defects  and  anomalies. 

The  knowledge  of  a  foreign  language  enables  us  to 
consult  works  composed  in  it,  and  to  hold  oral  or  written 
intercourse  with  those  who  employ  it.  The  language  of 
a  nation  is  also,  in  many  instances,  the  only  evidence  of 
its  origin ;  and  it  exhibits  various  peculiarities  regarding 
its  circumstances  and  character,  which  cannot  frequently 
be  learned  from  any  other  source.  Comparative  Philo- 
logy removes  various  difficulties  and  obscurities  attend- 
ing the  study  of  dead  languages.  It  also  furnishes  means 
of  determining  the  origin,  migrations  and  affinities  of  na- 
tions, and  thus  frequently  supplies  defects  in  History. 

§  2.  OP  ETHNOGRAPHY. — Foundations  of  Ethnography. — Sources  of 
Errors. — How  these  may  be  detected. — Uses  of  Ethnography. 

Ethnography  consists  chiefly  of  primary  facts,  derived 
from,  public  records,  the  narratives  of  travelers,  local  his- 
tories, works  of  art,  and  direct  personal  observations. 
Owing  to  the  immense  extent  of  the  subject,  the  latter 
can  form  only  a  very  small  part  of  it.  The  facts  are  also 
liable  to  change,  more  or  less,  from  age  to  age,  or  even 
from  year  to  year :  and  hence  the  accounts  of  the  past 
may  not  apply  to  the  present.  Various  errors  have  also 
arisen  from  the  national  or  individual  prejudices  of  those 
from  whose  works  a  great  portion  of  ethnographical 
treatises  is  derived.  Hence  many  of  them  teem  with  er- 
rors. But  these  may  generally  be  detected  by  compar- 
ing the  statements  of  various  writers  with  each  other,  or 
by  having  recourse  to  original  and  reliable  authorities. 
Those  who  write  from  their  personal  knowledge  are  gen- 
erally more  reliable  than  such  as  derived  their  informa- 
tion from  others :  but  there  are  great  differences,  in  these 
respects;  and  we  may  generally  trust  more  to  the  care 
and  veracity  of  an  author  than  to  his  means  of  acquiring 
knowledge. 

A  competent  knowledge  of  Ethnography  is  requisite 
to  a  proper  understanding  of  numerous  statements  and 
allusions  found  in  the  works  of  authors  who  treat  of 
times  or  countries  other  than  our  own.  It  is  also  indis- 
pensable to  the  proper  study  of  History,  while  it  tends 


392  MIXED  KNOWLEDGE.       [CHAP.  XXV. 

to  remove  the  narrow-mindedness  which  is  npt  to  accom- 
pany an  acquaintance  with  only  one  state  of  society.  It 
enables  us  to  compare  and  trace  the  effects  of  different 
laws*  opinions,  institutions  and  manners.  Thus  we  can 
form  a  proper  estimate  of  our  own  condition,  while  we 
receive  suggestions  for  its  improvement.  By  the  same 
means,  also,  we  can  easily  avoid  the  dangerous  error  of 
assuming  that  our  own  morals,  manners  and  institutions 
are  perfect  standards  of  excellence,  when,  in  reality,  they 
may  be  far  otherwise.  We  also  learn  the  wants  of  oth- 
ers, so  that  we  can  take  proper  steps  to  supply  them. 
Besides  these  advantages,  Ethnography  answers  several 
of  the  same  purposes  as  Geography,  to  which  it  is  close- 
ly allied. 

§  3.  OF  TECHNOLOGY. — How  an  Art  is  distinguished  from  a  Science. 
— Foundations  of  Art. — Its  Relations  to  Science. — Requisites  to 
Proficiency. — Superiority  of  Arts  based  on  Inductions. — Theory 
and  Practice. — Manual  Dexterity. — Source  of  Improvements. — 
Importance  and  Relations  of  Rhetoric. — Education. — How  related 
to  Rhetoric. — Its  Importance. 

An  Art  is  distinguished  from  a  Science  chiefly  by  its 
consisting  of  rules  and  directions  for  effecting  some  ob- 
ject, and  a  general  absence  of  discussions  regarding  sim- 
ple knowledge.  Art  considers  how  a  certain  thing  is  to 
be  done,  while  science  shows  what  is.  Yet,  as  the  prop- 
er mode  of  accomplishing  a  certain  end,  depends  on  a 
knowledge  of  the  subject,  and  this  must  often  be  discuss- 
ed in  a  treatise  on  the  art,  the  boundaries  of  Art  and  Sci- 
ence are  not  always  well  defined.  Many  sciences  include 
what  might  properly  be  termed  arts.  Thus,  Geometry 
includes  the  art  of  drawing  geometrical  figures,  and 
Astronomy,  that  of  making  astronomical  observations. 
Such  arts  are  properly  classed  with  the  sciences  to  which 
they  refer,  when  they  form  necessary  parts  of  them. 

Art  borrows  the  knowledge  which  it  requires  from 
whatever  sources  afford  it ;  and  it  often  gives  some  de- 
gree of  connection  to  a  great  many  scientific  elements, 
which  have  not  been  incorporated  into  any  regular  sci- 
ence. As  new  applications  of  the  sciences  may  be  made, 
without  any  increase  of  their  number,  the  arts  generally 
multiply  much  faster  than  the  sciences.  Several  arts 
may  be  based  on  a  single  science ;  and,  on  the  other 
hand,  a  single  art  often  derives  materials  from  several 
sciences. 


SJEC.  3.]  TECHNOLOGY.  390 

The  dependence  of  Art  and  Science  on  each  other  is 
often  mutual.  The  art  of  the  optician  is  necessary  to 
unfold  the  mysteries  and  wonders  of  the  physical  crea- 
tion, whether  in  the  Sun  or  in  a  mite,  while  the  optician 
is  dependent  on  the  sciences  of  Geometry  and  Optic. 
The  value  of  the  air-pump  is  felt  in  several  sciences ; 
and  the  art  of  calculation  is  required  in  a  still  greater 
number.  On  the  other  hand,  Art  is  based,  more  or  less, 
on  Science;  and  it  is  generally  impracticable  to  master 
any  division  of  the  former  without  acquiring  some  knowl- 
edge of  the  sciences  on  which  it  is  dependent.  Tins  and 
careful  practice  are  the  principal  requisites  to  proficiency 
in  an  art. 

While  we  act  only  on  empirical  knowledge,  improve- 
mepts  must  be  accidental,  and  one  advance  does  not  pre- 
pare the  way  for  another,  as  all  empirical  arts  are  neces- 
sarily chained  down  to  one  uniform  course,  and  anything 
beyond  the  usual  routine  is  out  of  the  question.  On  the 
other  hand,  if  we  are  guided  by  inductions,  our  processes 
are  more  certain  in  their  results,  and  more  susceptible  of 
improvement,  because  we  are  in  possession  of  the  gener- 
al law.  Thus,  the  mere  fact  that  a  certain  medicine  has 
been  found  beneficial  in  certain  cases,  does  not  inform  us 
what  are  the  circumstances  on  which  its  efficacy  depends, 
or  what  are  the  principles  of  its  operation :  and  conse- 
quently we  should  be  apt  to  use  it  where  its  effects  would 
be  positively  detrimental.  So,  if  a  shipbuilder  finds  that 
a  vessel  of  one  form  sails  faster  than  another,  of  a  differ- 
ent form,  this  knowledge  does  not  enable  him  to  make 
any  improvements,  while  a  knowledge  of  Mechanic  and 
Hydric  would  unfold  the  principle  on  which  the  superior 
sailing  depended,  and  thus  enable  him  to  build  vessels  of 
a  still  better  form. 

A  thing  cannot  be  good  in  theory  and  bad  in  practice : 
for  this  is  only  saying,  in  other  words,  that  rules  based 
on  a  wide  and  correct  knowledge  of  the  subject,  are  in- 
ferior to.  those  founded  on  narrow  and  inaccurate  views. 
We  should  not  confound  what  is  really  with  what  is  only 
apparently  good.  A  theory  may  be  very  plausible,  and 
yet  quite  erroneous,  just  as  an  argument  may  be  very 
specious,  and  yet  quite*  fallacious :  but  a  theory  which  is 
bad  in  practice,  is  bad  altogether ;  and,  therefore,  what- 
ever is  really  good  in  theory  must  be  equally  so  in  prac- 
tice, if  it  can  be  put  in  practice.  The  empiric  thinks  that 

R2 


394  MIXED  KNOWLEDGE.       [CHAP.  XXV. 

he  alone  is  guided  by  experience,  when,  in  truth,  lie  is 
only  guided  by  a  narrow  experience,  while  those  whom 
he  decries  are  guided  by  scientific  generalizations.  He 
also  falls,  in  many  instances,  into  the  further  blunder  of 
mistaking  his  own  erroneous  inferences  for  the  voice  of 
experience.  This  teaches  us  simply  what  we  have  expe- 
rienced :  and,  in  order  to  apply  it  safely  to  the  future, 
we  must  reason  on  the  subject,  or,  in  other  words,  have 
recourse  to  theory. 

Although  a  certain  degree  of  practice  and  manual 
dexterity  often  requires  to  be  combined  with  theoretical 
knowledge,  in  order  to  render  a  person  an  adept  in  the 
art,  yet  the  former,  without  the  latter,  is  generally  of  lit- 
tle avail.  Thus,  a  man  ignorant  of  Anatomy  and  Physi- 
ology cannot  be  a  good  surgeon,  however  long  he  may 
have  practiced  the  art :  for,  in  many  cases,  he  cannot 
know  what  operation  ought  to  be  performed,  or  how  it 
can  best  be  effected,  while,  in  other  cases,  he  will  operate 
where  no  operation  is  required.  Even  in  the  most  pure- 
ly mechanical  arts,  the -hand  is  greatly  aided  by  an  intel- 
ligent head :  and  the  value  of  scientific  knowledge,  in 
such  arts,  is  shown  by  the  fact  that  many  important  im- 
provements have  been  made  in  them  by  men  of  science, 
who  were  not  operative  artisans  at  all,  after  the  empirics 
had  long  employed  the  old  method,  without  ever  dream- 
ing of  a  better. (31) 

Among  the  intellectual  arts,  Rhetoric  has  long  held  a 
conspicuous  place.  The  Greeks  applied  it  mostly  to  pub- 
lic speaking,  :  but  it  is  equally  applicable  to  all  didactic 
discourse.  It  is  based  chiefly  on  Psychology,  Logic  and 
Philology ;  and  it  discusses  all  discourse  which  is  design- 
ed to  produce  conviction,  whether  this  be  the  sole  im- 
mediate object  or  not.  It  differs  essentially  from  the 
emotional  arts,  in  regarding  emotion  only  as  a  means 
of  securing  conviction,  and  influencing  the  conduct  of 
those  addressed.  Grammar  treats  of  style  only  so  far 
as  literal  accuracy  is  concerned,  while  Rhetoric  consid- 
ers also  those  qualities  of  style  which  affect  the  judge- 
ment and  the  feelings.  As  its  principles  are  drawn 
from  other  departments,  and  it  is.  chiefly  occupied  with 
the  means  of  effecting  a  particular  end,  Rhetoric  is  prop- 
erly classed  with  the  intellectual  arts,  although  some 
have  ranked  it  as  a  science. 

A  person's  future  condition  often  depends  on  his  being 


SEC.  3.]  TECHNOLOGY.  395 

convinced  of  a  certain  truth,  which,  if  believed,  will  pow- 
erfully affect  both  his  feelings  and  his  conduct.  But  he 
rejects  it,  owing  to  the  advocate's  failing  to  present  it  in 
a  proper  manner.  Hence  the  importance  of  knowing 
the  best  means  of  communicating  truth,  and  leading 
those  addressed  to  perform  the  requirements  of  duty. 

The  art  of  Education  has  much  in  common  with  Rhet- 
oric, since  children  possess  the  same  powers  and  suscep- 
tibilities as  adults,  although  in  an  immature  degree. 
Hence  the  same  rules  are  applicable,  when  modified  to 
suit  the  particular  condition  of  those  addressed.  But 
here  the  field  is  much  wider,  since  the  object  is,  not 
merely  to  instruct,  but  also  to  train  and  develop  the  fac- 
ulties in  a  proper  manner.  The  comparatively  volatile 
and  negligent  character  of  the  young,  also,  renders  it  nec- 
essary to  employ  measures  which  are  not  requisite  in  the 
case  of  adults,  in  order  to  secure  proper  attention,  with- 
out which  little  real  progress  can  be  made  either  in  train- 
ing or  instructing. 

The  subject  of  education  cannot  be  overestimated,  as 
it  forms  the  moral  character,  and  exerts  a  very  extensive 
influence  on  the  physical  and  intellectual.  It  properly 
includes,  however,  the  instructions  and  examples  of  all 
with  whom  the  young  have  intercourse,  whether  pro- 
fessed teachers,  parents  or  associates. 

A  knowledge  of  this  subject  is  useful  to  parents  and 
guardians,  as  well  as  to  ordinary  teachers,  on  several  ac- 
counts. It  enables  them  to  perform  aright  their  own 
part  in  the  business  of  education,  in  which  the  parental 
is  of  more  consequence  than  any  other,  as  its  influence  is 
most  constant  and  powerful.  A  parent  who  is  aware  of 
the  evils  resulting  from  a  failure  of  his  duty,  in  this  re- 
spect, and  the  benefits  which  flow  from  a  contrary  course, 
will  confer  permanent  good  on  his  offspring,  of  which 
those  who  are  ignorant  on  the  subject  have  no  concep- 
tion. '  Such  knowledge  also  enables  parents  to  select  the 
best  accessible  teachers  for  their  children,  whereas  igno- 
rance often  hands  them  over  to  educational  quacks,  who 
profess  and  promise  whatever  will  increase  their  notori- 
ety and  gains,  the  sole  objects  of  their  labors.  Thus  it 
has  sometimes  happened  that  children  who  were  badly 
educated  at  home,  were  consigned  to  worse  teachers 
abroad :  and  when  they  afterwards  followed  evil  ways, 
the  disciples  of  darkness  held  them  up  as  a  striking  proof 


396  PARTICULAR  KNOWLEDGE.    [CHAP.  XXVI. 

of  the  uselessness  of  education.  Yet  such  results  do  not 
in  the  least  disprove  the  great  truth  that  a  good  educa- 
tion (not  any  Irind  of  education)  secures  right  conduct 
in  after  life. 


CHAPTER  XXVI. 

OF   PARTICULAR   KNOWLEDGE. 

§  1.  OF  HISTORY. — Foundations  and  character  of  History. — Its  Uses. 

—  Cautions. — Empiricisms. — Inductions. — Limits  of  History. — 
Philosophy. — Prophecy. — Causes  and  Effects. — Selection  of  Events. 

—  Best  Historian. — First  Merit  of  History. — Frequent  Errors. — 
Two  Classes  of  Historians. — Principal  original  Authorities. — Cau- 
tion.—  Common  Defect. — Observations  on  Study, — Traditional 
Narratives. 

HISTORY  is  founded  on  personal  observation,  the  testi- 
mony of  others,  and  documents  relating  to  the  events  re- 
corded. The  character  of  its  statements  is  to  be  ascer- 
tained by  the  ordinary  criterions  of  testimony,  as  if  we 
were  inquiring  into  the  truth  of  a  narrative  regarding  a 
recent  occurrence,  in  our  own  neighbourhood.  As  the 
events  recorded  are  neither  necessary  nor  general,  its 
truths  are  all  contingent  and  particular. 

History  not  only  gratifies  a  natural  curiosity  regarding 
the  actions  of  mankind,  and  thus  affords  a  refined  pleas- 
ure, to  persons  of  all  ages,  but  it  also  furnishes  materials 
for  various  sciences  and  arts :  for  what  has  happened,  in 
certain  circumstances,  must  always  happen  where  the  de- 
termining agencies  are  the  same,  although  there  be  sev- 
eral minor  differences.  Hence  we  can  often  determine 
the  results  of  certain  agencies,  before  they  have  become 
matters  of  History.  Here  we  also  learn  various  lessons 
regarding  the  influence  of  particular  institutions,  princi- 
ples, and  opinions :  we  are  aided  in  ascertaining  the  char- 
acter of  man,  what  circumstances  are  favorable  to  the 
due  development  of  his  faculties  and  to  national  prosper- 
ity, and  whence  spring  public  distress  and  misery ;  and 
we  are  warned  to  exercise  proper  caution  in  our  inter- 
course with  others. 

Scientific  and  artistic  histories  furnish  many  sugges- 
tions and  warnings  to  those  who  cultivate  the  different 
branches,  as  has  been  already  remarked. 


SEC.  1.]  HISTORY.  397 

History  is  likewise  a  powerful  instrument  of  moral 
discipline  and  enjoyment.  For  virtuous  feelings  are  ex- 
cited, strengthened,  and  gratified  by  tracing  the  career 
of  the  good,  while  vicious  passions  are  checked  by  the 
exhibitions  which  are  made  of  their  repulsive  nature,  and 
the  consequences  to  which,  sooner  or  later,  they  uniform- 
ly lead.  Conception  enables  us,  in  a  great  measure,  to 
view  the  events  of  History  like  spectators  of  the  scenes 
and  events  described,  while  sympathy  with  laudable  ac- 
tions conveys  to  us  a  part  of  the  joy  of  those  who  per- 
formed them,  and,  at  the  same  time,  stimulates  to  emu- 
lation. On  the  other  hand,  the  indignation  excited  by  a 
vivid  contemplation  of  base  or  vile  actions,  strengthens 
our  resolutions  to  beware  of  them,  and  pursue  a  different 
course.  Thus  the  achievements  of  a  great  and  good  man 
become  the  common  inheritance  of  mankind,  while  the 
course  of  a  contrary  character  furnishes  a  perpetual 
warning. 

In  order  to  secure  such  advantages,  the  events  must 
be  fairly  and  accurately  depicted,  and  we  must  beware 
of  receiving  the  partial  and  distorted  narratives  of  un- 
principled men  as  faithful  delineations.  If  an  historical 
work  is  not  substantially  accurate,  and  does  not  exhibit 
men  and  events  nearly,  if  not  precisely,  as  they  were,  it 
will  only  mislead  and  corrupt,  instead  of  enlightening 
and  improving. 

Empirical  generalizations  are  properly  use^  in  History, 
to  render  its  statements  more  concise  and  forcible :  but 
we  should  beware  of  the  fallacy  of  irrelevant  empiricism, 
which  abounds  in  various  historical  works. 

Inductions  have  frequently  fyeen  attempted  to  be  in- 
troduced into  History :  but  they  are  quite  alien  to  its 
nature  and  objects:  and  although  the  truths  of  History 
are  properly  employed  in  establishing  inductions,  in  those 
branches  of  knowledge  to  which  they  properly  belong, 
yet  the  attempt  to  introduce  them  here  produces  only  in- 
congruity, distraction  of  attention,  and  error.  The  duty 
of  the  historian  is  confined  to  relating  past  occurrences, 
with  their  immediate  causes  and  effects,  so  far  as  these 
can  be  certainly  ascertained,  leaving  every  man  to  make 
such  applications  of  his  narrative  as  he  deems  proper. 

With  regard  to  futurity,  it  evidently  lies  wholly  be- 
yond the  province  of  History;  and  consequently  the  his- 
torian wanders  altogether  out  of  his  way  when  he  spec- 


398  PARTICULAR  KNOWLEDGE.    [CHAP.  XXVI. 

tilates  about  the  future :  he  has  quite  as  little  to  do  with 
prophecy  as  with  philosophy. 

A  knowledge  of  causes  and  effects  forms  one  of  the 
most  important  parts  of  History :  but  we  should  beware 
of  receiving  as  true,  statements  made  on  this  subject, 
where  it  does  not  appear  that  they  are  anything  more 
than  conjectural  opinions.  Fallacies  of  causation  abound 
in  many  histories ;  and  actions  are  often  attributed  to 
motives  which  had  no  effect  in  their  production,  while 
their  real  causes  are  not  set  forth.  Motives  must  gener- 
ally be  learned  from  the  conduct  of  the  parties,  their 
statements  being  frequently  mere  pretences,  or  the  re- 
sults of  self-deception.  The  real  motives  were  not  un- 
frequently  very  different,  even  from  what  the  parties 
themselves  believed:  for  men  wish  to  stand  fair  with 
their  own  consciences,  and  thus  frequently  mislead  them- 
selves regarding  the  true  character  of  their  motives. 

Remote  causes  and  consequences  are  not  easily  traced, 
with  any  degree  of  certainty ;  and  they  run  to  an  indefi- 
nite extent.  The  consideration  of  them,  therefore,  forms 
no  part  of  the  historian's  duty,  as  it  would  produce 
doubt  and  distraction,  rather  than  instruction  or  enter- 
tainment. 

Actual  occurrences  are  far  too  numerous  to  be  men- 
tioned in  History,  while  most  of  them  are  too  trivial  or 
unimportant  to  be  worth  recording :  and  few  things  are 
a  better  tesfr  of  an  historian's  judgement  than  the  mode 
in  which  he  makes  his  selection.  Some  weary  us  with 
commonplace  details  and  gossip,  neither  interesting  nor 
instructive,  while  the  most  important  parts  of  the  subject 
are  either  omitted  or  stated  vaguely.  Others  are  equal- 
ly uninviting  and  uninstructive  on  account  of  their  ex- 
treme conciseness,  and  the  consequent  indefiniteness  and 
obscurity  of  their  statements. 

The  best  historian  is  he  who  avoids  prolixity,  and  yet 
sets  the  events  vividly  before  us,  as  they  really  were,  so 
that,  after  reading  his  narrative,  we  may  have  such  a  no- 
tion of  them  as  if  we  had  actually  witnessed  them.  While 
lie  totally  excludes  what  is  not  worth  recording,  and  de- 
votes little  space  to  ordinary  occurrences,  which  we 
could  accurately  conjecture,  he  relates  all  that  is  requi- 
site to  a  clear  and  accurate  exhibition  of  the  events  and 
incidents,  as  he  seizes  and  faithfully  depicts  the  charac- 
teristic traits. 


SEC.  1.]  HISTORY.  399 

The  first  merit  of  a  history  is,  truth,  without  which  it 
does  not  deserve  the  name.  Hence,  in  selecting  works 
for  study,  those  which  are  scrupulously  accurate  and  im- 
partial, should  have  a  preference  over  all  others.  These 
excellences  are  frequently  wanting  in  histories  other- 
wise written  with  much  ability.  Some  historians  exag- 
gerate or  distort  for  the  sake  of  effect ;  not  a  few  mis- 
represent from  prejudice  or  malicious  motives;  and  oth- 
ers frame  their  statements  so  as  to  support  their  own 
views,  theories  or  secret  purposes,  while  many  err  from 
hurry  or  carelessness. 

The  statements  are,  in  many  instances,  literally  true ; 
and  yet  they  convey  a  false  impression,  because  some  im- 
portant points  are  omitted,  or  not  related  with  sufficient 
fullness.  Consequently  the  reader  is  apt  to  be  misled, 
and  to  form  an  erroneous  opinion  of  the  people  or  the  oc- 
currences. In  other  cases,  general  statements  are  made, 
which  conflict  with  facts  as  numerous  as  those  on  which 
they  are  based.  Fallacious  appeals  to  the  passions  are 
not  unfrequent,  especially  in  narratives  written  by  parti- 
sans. Opprobrious  epithets  are  freely  applied  to  their 
opponents,  while  they  are  equally  profuse  in  commenda- 
tions of  their  friends,  set  off  by  sneers,  laudatory  maxims, 
or  feeble  expressions  of  praise  or  censure,  where  truth 
required  much  stronger  language. 

History  is  vitiated  by  painting  men  in  colors  which  are 
either  brighter  or  darker  than  the  reality :  for  we  are 
thus  misled  regarding  the  characters  delineated  and  the 
influence  of  certain  agencies  on  communities.  It  is  dan- 
gerous to  believe  that  mankind  are  more  honest  and 
faithful  than  they  really  are,  while  we  wrong  them,  and 
disturb  our  own  peace  of  mind  by  attributing  to  them 
vices  of  which  they  are  innocent.  Nations  and  individ- 
uals have  often  suffered  severely,  owing  to  misplaced 
confidence,  arising  from  their  ignorance  of  the  dark  side 
of  human  nature.  On  the  other  hand,  the  generous  and 
benevolent  feelings  of  the  mind  are  deadened,  and  inter- 
course with  others  is  rendered  unnecessarily  difficult,  by 
our  being  led  to  believe  that  all  mankind  are  knaves  and 
liars.  Hence  the  propriety  of  selecting  those  historians 
who  neither  blacken  nor  whitewash,  but  represent  both 
the  lights  and  the  shades  precisely  as  they  were. 

Historians  may  be  divided  into  two  great  classes — 
original  authorities,  who  record  facts  never  before  writ- 


400  PARTICULAR  KNOWLEDGE.    [CHAP.  XXVI. 

ten — and  compilers,  who  draw  their  materials  exclusively 
from  previously  written  narratives  or  compositions.  Not 
unfrequently  an  author  belongs  to  both  classes. 

Of  original  authorities,  some  write  from  hearsay  only, 
and  others  record  their  personal  observations.  The  for- 
mer are  generally  entitled  to  much  less  credit ;  and  when 
the  events  related  were  remote  from  their  own  time,  they 
are  seldom  implicitly  reliable.  Sometimes  it  is  difficult 
to  determine  to  which  head  a  statement  belongs ;  and, 
in  such  cases,  we  must  be  guided  by  a  knowledge  of  the 
author's  character  and  circumstances. 

Among  original  authorities,  the  narratives  of  personal 
witnesses,  public  records,  statutes,  treaties,  inscriptions, 
official  documents,  and  information  derived  immediately 
from  eyewitnesses,  are  generally  the  best.  But  many 
of  these  are  by  no  means  unexceptionable  ;  and  it  some- 
times happens  that  a  compilation  is  more  accurate  than 
any  single  authority  from  which  it  is  composed. 

In  Ancient  History,  it  is  requisite  to  ascertain  the  gen- 
uineness of  the  composition,  as  several  are  spurious;  and 
the  same  remark  applies  to  some  modern  narratives  also. 

Several  narratives  relate  chiefly  military  and  political 
transactions,  while  they  profess  to  give  the  entire  history 
of  the  country.  Wars  are  always  effects  of  certain  opin- 
ions :  and  unless  these  are  delineated,  a  military  history 
is  like  a  picture  of  a  battle-field,  which  exhibits  chiefly 
fury  and  carnage.  No  history  of  a  nation  or  community 
deserves  that  title,  unless  it  gives  a  view  of  the  progress 
and  changes  of  religious  opinions,  morals,  law,  science, 
art,  literature,  and  domestic  life  and  manners.  These  are 
the  most  important  subjects  of  History ;  and  an  accurate 
delineation  of  them  forms  the  best  exhibition  of  a  na- 
tion's real  state  and  progress. 

In  studying  History,  we  should  first  obtain  a  general 
view  of  the  whole  course  of  events,  from  the  earliest 
times,  including  the  rise  and  fall  of  states,  the  intercourse 
of  one  country  with  another,  and  the  general  condition 
of  mankind,  during  the  various  periods.  This  may  be 
acquired  from  a  good  set  of  historical  charts,  and  cor- 
responding outlines.  We  can  afterwards  study  to  ad- 
vantage the  history  of  any  particular  country,  which  we 
cannot  well  do  till  we  learn  the  outlines  of  General  His- 
tory. 

The  most  advisable  course  then  is,  to  take  the  best  ac- 


SEC.  1.]  HISTORY.  401 

cessible  general  compilation,  as  a  text-book,  and  to  read 
and  compare  original  narratives  and  documents  as  the 
importance  of  the  particular  subjects  or  periods,  and  our 
circumstances,  require  or  admit.  Original  narratives 
generally  cover  only  a  small  portion  of  a  nation's  his- 
.  tory  ;  and,  therefore,  it  is  desirable  to  have  a  good  com- 
pilation as  a  general  guide.  Yet  the  former  are  usually 
more  full  and  graphic,  and  frequently  more  accurate  in 
details. 

After  acquiring  the  outlines  of  General  History,  and 
a  good  knowledge  of  the  events  of  Holy  Writ,  our  own 
country  should  engage  our  attention,  unless  our  circum- 
stances permit,  and  our  tastes  lead,  us  to  study  the  his- 
tory of  the  principal  nations  of  ancient  and  modern  times. 
In  that  case,  it  is  best  to  follow  the  course  of  events,  be- 
ginning with  the  earliest,  and  coming  down  gradually  to 
the  present  day. 

Where  we  cannot  study  the  history  of  every  cele- 
brated nation,  we  should  select  those  which  are  most  in- 
teresting, either  on  account  of  the  mental  development 
and  general  intelligence  of  the  people,  or  of  its  connec- 
tion with  our  own. 

Before  commencing  the  study  of  an  author,  we  should 
ascertain  his  relation  to  the  facts  he  professes  to  relate, 
and  the  nature  of  the  testimony  on  which  his  statements 
are  based.  This  will  sometimes  cause  a  little  delay  and 
additional  labor:  but  these  are  well  repaid, by  the  checks 
which  they  furnish  against  receiving  erroneous  state- 
ments for  historical  truths,  which  Avill  frequently  be  the 
result  of  neglecting  those  precautions. 

We  should  ahvays  endeavor  to  form  an  accurate  and 
lively  conception  of  the  events  and  scenes,  so  that  they 
may  be  represented  to  our  minds  as  nearly  like  the  orig- 
inals as  possible.  For  this  is  requisite,  in  order  to  avoid 
erroneous  views,  and  to  feel  that  degree  of  interest  in  the 
narrative  which  is  requisite  to  agreeable  or  profitable 
study.  It  is  impracticable  to  secure  the  principal  ad- 
vantages of  this  study  without  an  accurate  conception 
of  the  events,  and  of  the  characters  and  circumstances 
of  the  community  whose  history  we' peruse. 

In  regard  to  the  earliest  history  of  nations,  the  student 
will  readily  find  that,  although  it  may  have  long  existed 
in  a  written  form,  yet  it  is  generally  based  on  traditional 
accounts,  without  deriving  much  light  from  contempora- 


402  PARTICULAR  KNOWLEDGE.   [CHAP.  XX'VI. 

ry  written  narratives.  These  accounts  should  neither  be 
utterly  rejected  without  examination,  nor  implicitly  re- 
ceived. On  the  one  hand,  traditional  narratives  of  re- 
markable events  have  been  sometimes  handed  down, 
without  any  material  variation,  through  many  genera- 
tions. On  the  other  hand,  they  are  generally  liable  to 
be  greatly  corrupted,  during  their  transmission,  even 
where  they  were  originally  correct ;  and,  in  many  in- 
stances, they  are  totally  spurious,  being  the  result  of 
knavery  and  fraud,  operating  on  ignorant  credulity. 

It  is  true  that  pure  fiction  cannot  be  directly  imposed 
on  mankind  for  authentic  history :  yet  this  may  be  done 
indirectly;  and  the  circumstances  of  the  case,  compared 
with  the  character  of  the  tradition,  and  well  authentica- 
ted facts,  derived  from  other  sources,  will  generally  ena- 
ble us  to  ascertain  the  actual  truth.  In  the  absence 
of  any  corroboration  derived  from  present  facts  or  the 
testimony  of  History  or  Philology,  traditional  narratives 
are  seldom  entitled  to  any  weight :  and  where  they  are 
evidently  absurd,  or  contradicted  by  authentic  evidence, 
they  should  be  unhesitatingly  rejected.  On  the  other 
hand,  where  they  derive  corroboration  from  other  credi- 
ble sources,  and  are  neither  absurd  nor  at  variance  with 
known  truths,  they  may  be  safely  adopted  as  substantial- 
ly true,  save  that  they  are  very  rarely  reliable  as  to  num- 
bers, dates,  and  places. 

§  2.  Or  CHRONOLOGY.  —  Use  of  Chronology.  —  Epochs.  —  Means  of 
determining  Dates. 

A  knowledge  of  the  time  when  events  occurred  is 
necessary  in  order  to  understand  their  progress  and  con- 
nections :  for  otherwise  they  present  themselves  to  our 
memory  as  a  confused  and  unconnected  mass  of  facts. 
Hence  Chronology  forms  an  important  auxiliary  to  the 
right  understanding  and  remembering  of  History. 

In  order  to  determine  the  time  when  the  various 
events  occurred,  some  epoch  or  fixed  period  is  chosen, 
from  which  they  are  reckoned,  either  backward  or  for- 
ward, and  the  number  of  years  which  intervene  between 
it  and  an  event,  determines  the  time  of  the  occurrence. 

Various  epochs  have  been  chosen  by  different  nations : 
but  as  the  Christian  states  have  obtained  the  control  of 
the  world,  and  far  outstripped  the  rest  of  mankind  in  ev- 
ery important  respect,  the  epoch  of  our  Savior's  birth, 


SEC.  3.]  BIOGRAPHY.  403 

or  the  commencement  of  the  Christian  era,  which  they 
all  employ,  is  now  the  only  one  of  much  consequence. 

The  interval  between  an  occurrence  and  the  epoch  is 
ascertained  either  from  the  direct  statements  of  persons 
who  knew,  or  from  public  records,  or  from  computing  the 
length  of  the  various  periods  which  form  the  interval, 
from  the  testimonies  of  historians,  monumental  inscrip- 
tions, coins,  astronomical  phenomena,  &c. 

When  the  interval  between  two  epochs  has  been  as- 
certained, dates  reckoned  from  one  can  be  converted  into 
those  reckoned  from  another,  by  a  simple  process  of  ad- 
dition or  subtraction. (32) 

§  3.  OF  BIOGRAPHY. — Relations  of  Biography  to  History. — Its  Uses. 
—  Its  Advantages  and  Disadvantages,  compared  with  History.  — 
Common  Faults,  and  how  they  may  be  obviated  in  Study. — Char- 
acteristics of  good  Biographies. — Autobiographies. 

Owing  to  its  nature,  Biography  is  much  narrower  than 
History  in  its  range:  but  it  is  more  particular  in  its 
views,  and  gives  a  fuller  insight  into  individual  charac- 
ter. History  gives  an  account  of  communities  collective- 
ly, while  Biography  gives  an  account  of  the  compara- 
tively small  number  of  individuals  whose  lives  present 
something  remarkable,  and  worthy  of  remembrance. 
The  exact  line  which  separates  them,  is  not  very  clearly 
marked :  yet  the  general  distinction  is  obvious ;  and  in- 
deed the  two  cannot  properly  be  amalgamated.  Ac- 
counts of  occurrences  in  which  individuals  alone  were 
concerned,  and  which  did  not  directly  aifect  any  com- 
munity or  class,  are  out  of  place  in  History ;  and  narra- 
tives of  public  transactions  are  equally  irrelevant  in  Bi- 
ography. A  professed  history  which  consists,  in  reality, 
of  a  string  of  biographies,  is  apt  to  mislead  us,  as  the 
characters  of  the  individuals  whose  lives  are  recorded, 
may  have  differed  widely  from  that  of  the  community 
with  which  they  wrere  connected. 

Biography  so  closely  resembles  History  that  most  of 
the  remarks  made  in  the  preceding  section  are  equally 
applicable  here.  Biography,  however,  states  many  mi- 
nute .particulars  which  History  overlooks  ;  and  thus  it 
often  enables  us  to  form  more  definite  conceptions  than 
the  more  general  statements  of  History  admit;  and  it  is 
more  available  in  enabling  us  to  ascertain  how  an  indi- 
vidual of  a  certain  character  will  act,  in  given  circum- 


404  PARTICULAR  KNOWLEDGE.   [CHAP.  XXVI. 

stances.  At  the  same  time  it  is  of  comparatively  little 
use,  in  enabling  us  to  determine  the  effects  of  laws,  opin- 
ions and  institutions,  because  individual  peculiarities  fre- 
quently control  or  prevent  the  ordinary  results  of  those 
agencies,  which  become  conspicuous  only  when  we  view 
their  effects  on  nations  or  communities. 

As  biographies  are  generally  written  by  friends  or  ad- 
mirers, they  are  still  more  affected  by  prejudices  than 
histories.  The  characters  and  motives  of  the  principal 
personage  and  his  friends  are  often  represented  in  colors 
too  favorable,  while  those  of  their  opponents  or  rivals 
suffer  proportionally.  Hence  due  allowances  should  be 
made.  Where  the  biographer  is  unfriendly,  this  state 
of  things  is  reversed  ;  and  we  should  accordingly  lighten 
the  picture,  as  the  results  of  proper  investigation  require. 

Prolixity  is  a  common  fault  of  biographies ;  and  this 
is  not  unfrequently  carried  to  such  an  extent  that  the 
works  are  unworthy  of  general  perusal :  and  they  should 
be  used  only  for  occasional  reference,  when  we  wish  to 
learn  something  interesting  which  is  not  found  elsewhere, 
or  to  compare  the  statements  with  other  authorities. 

A  good  biography  gives  a  correct  and  vivid  represent- 
ation of  the  life  and  character  of  its  object,  of  the  vari- 
ous agencies  that  directly  influenced  him,  and  of  the  im- 
mediate effects  of  his  words  or  actions  upon  others.  It 
avoids  the  extremes  of  adulation  and  detraction,  dull  pro- 
lixity and  vague  generalities. 

In  reading  autobiographies,  we  should  guard  particu- 
larly against  paralogisms  of  testimony :  for  the  writers 
often  impose  on  themselves  unconsciously,  and  conse- 
quently are  very  apt  to  mislead  others.  A  man  is  oft- 
en greatly  mistaken  in  his  estimate  of  his  own  charac- 
ter, opinions,  motives  and  conduct :  and,  therefore,  if  he 
writes  his  own  life,  the  work  will  be  very  apt  to  abound 
with  errors,  of  many  of  which  he  may  have  no  concep- 
tion or  suspicion. 


SEC.  1.]  GENEEAL  OBSERVATIONS.  405 


CHAPTER  XXVII. 

OF   THE   KNOWLEDGE    OF   FUTURITY. 

§  1.  OF  THE  KNOWLEDGE  OF  FUTURITY  IN  GENERAL.— Common  De- 
sires regarding  the  Future. — Why  not  gratified. — Future  Things 
which  can  be  known,  and  advantages  of  knowing  them. — Proba- 
bility often  sufficient. 

A  KNOWLEDGE  of  the  past  is  of  no  value  except  as  it 
affects  the  present  or  the  future:  and  as  the  present  mo- 
ment is  incessantly  running  into  the  past,  while  the  fu- 
ture will  never  terminate,  some  knowledge  regarding  it 
is  both  important  and  desirable.  Although  such  knowl- 
edge is  narrower  than  what  we  may  acquire  regarding 
the  past,  yet  it  may  be  so  extensive  as  to  furnish  no  rea- 
son to  regret  its  smaller  extent. 

The  anxiety  of  mankind  to  know  the  principal  events 
of  their  future  lives,  appears  from  the  general  and  long- 
continued  prevalence  of  many  superstitious  arts,  which 
professed  to  accomplish  this  purpose,  but  which  are  only 
delusions,  resulting  from  thoughtless  credulity,  prejudice 
and  knavery,  as  appears  both  from  experience  and  rea- 
son. The  Most  High  has  wisely  and  graciously  covered 
the  particular  events  of  our  future  lives  with  an  impene- 
trable veil.  If  evil  awaits  us  which  we  cannot  obviate, 
it  is  enough  when  it  comes ;  and  if  we  receive  some  un- 
expected good,  it  is  the  more  agreeable  for  not  having 
been  anticipated. 

While  some  things  are  thus  concealed,  and  all  attempts 
to  foreknow  them  are  fruitless,  there  are  many  future 
events  that  we  may  foresee,  and  which  it  is  of  the  utmost 
consequence  that  we  should.  The  farmer  must  know 
that  summer  and  winter  will  return  ;  otherwise  he  would 
not  be  justified  in  toiling  long  and  hard,  and  incurring 
great  expense,  to  prepare  and  sow  his  fields :  and  we 
must  know  how  persons  of  a  certain  character  generally 
act,  when  placed  in  given  circumstances ;  otherwise  we 
could  not  safely  trust  others  with  property,  or  employ 
them  to  perform  important  business.  So  it  is  always  of 
great  .importance  that  we  should  know  the  general  re- 


406  KNOWLEDGE  OF  FUTURITY.  [CHAP.  XXVII. 

suits  of  certain  lines  of  conduct ;  otherwise  we  should  be 
strongly  disposed  to  follow  that  course  which  is  most 
agreeable  at  the  present  time,  without  paying  any  proper 
regard  to  the  distant  future.  And  indeed  this  is  one  of 
the  most  common  and  fatal  errors  that  men  ever  commit. 

If  all  the  unprincipled  persons  in  the  world  would  em- 
ploy the  means  within  their  reach,  to  discover  the  cer- 
tain and  unavoidable  results  of  their  present  conduct, 
they  would  see  a  picture  which  would  tend  very  power- 
fully to  lead  them  into  better  courses.  And  if  many  pa- 
rents would  examine  into  the  inevitable  results  of  the 
evil  training  which  they  give  their  children,  and  the  good 
effects  of  a  proper  course,  they  would  discard  the  former 
and  adopt  the  latter.  But  a  foolish  curiosity  to  know 
particular  future  events,  has  frequently  been  combined 
with  a  supine  indifference  regarding  the  individual's  fu- 
ture destiny. 

In  many  cases,  certainty  regarding  the  future  is  unat- 
tainable ;  but  we  can  arrive  at  a  high  degree  of  proba- 
bility, by  reasoning  from  the  circumstances  of  the  case, 
the  effects  of  agencies  known  to  be  operative,  or  present 
signs  of  futurity :  and,  in  all  cases  of  this  kind,  probabil- 
ity suffices,  for  practical  purposes.  Thus,  in  regard  to 
the  way  in  which  individuals  will  act,  in  given  circum- 
stances, we  are  sometimes  disappointed :  but  if  we  use 
due  caution,  such  disappointments  will  be  very  rare.  So, 
although  nothing  is  more  uncertain  than  the  life  of  an 
individual,  yet  the  average  duration  of  human  life,  in  a 
large  community,  varies  little,  from  year  to  year.  Even 
the  variations  caused  by  a  change  in  the  determining 
agencies,  such  as  famines  or  pestilences,  can  generally 
be  predicted  with  considerable  accuracy. 

§  2.  SOURCES  OF  OUR  KNOWLEDGE  OF  FUTURITY. — Necessary  and 
Hypothetical  Truths  independent  of  Time. — Two  Classes  of  Con- 
tingent Truths. — Source  of  our  Knowledge  of  the  future  Perma- 
nence of  Natural  Laws. — Proofs  that  the  Termination  of  the  pres- 
ent Course  of  Nature  is  very  remote. — (1)  Astronomical  Argu- 
ment.—(2)  Geological  Argument.— (3)  Historical  Argument. — 
(4)  Argument  from  Prophecy. — Inferences. — Means  of  knowing 
particular  future  Events. — Presentiments. — Extent  of  our  Knowl- 
edge of  Futurity. — Erroneous  Dogma. 

Necessary  and  hypothetical  truths  are,  from  their  very 
nature,  independent  of  time  and  place,  and,  therefore,  as 
for  the  past  and  future  as  for  the  present.     The 


SEC.  2.]  ITS  SOURCES.  407 

propositions  of  Mathematics,  for  instance,  will  be  as  true 
at  any  future  time  as  they  are  to-day ;  and  if  a  certain 
consequence  is  necessarily  implied  in  a  supposition  now, 
it  will  be  equally  implied  forever. 

With  respect  to  contingent  truths,  the  case  is  different. 
These  consist  of  two  classes,  general  and  particular.  The 
former  comprises  most  of  scientific  cognitions,  exclusive 
of  those  of  Mathematics,  which  are  all  necessary  truths. 
The  latter  express  only  particular  occurrences,  and  there- 
fore apply  neither  to  previous  nor  to  subsequent  times. 
When  we  say — "Alexander  the  Great  conquered  the 
Persian  Empire,"  we  express  only  a  particular  event, 
which  will  never  occur  again :  but  when  we  say — "  all 
vertebrate  animals  possess  a  brain,"  we  express  a  truth 
which  held  true  in  past  times,  and  will  do  so,  as  long  as 
the  present  system  of  the  world  is  upheld.  So,  the  law 
of  gravitation,  and  the  properties  of  heat,  light,  and  elec- 
tricity, are  equally  ^permanent;  and  the  structure  of  ev- 
ery species  of  organic  beings  will  be  what  it  now  is,  as 
long  as  the  species  exists. 

A  knowledge  of  the  operation  of  a  constant  and  un- 
changing agent  informs  us  of  its  future  effects,  when  we 
have  learned  what  they  are  in  one  case:  and  thus  we 
know  an  indefinite  number  of  future  truths,  including  the 

freater  portion  of  all  general  contingent  truths.  We 
now  that  the  laws  of  nature  will  be  the  same  hereafter 
as  they  are  now,  because  the  same  agencies  will  operate, 
and  in  the  same  circumstances.  Nothing  short  of  a  mi- 
raculous operation  of  the  Deity  would  alter  those  agen- 
cies or  circumstances :  and  we  know  that  he  will  not  so 
interfere.  Temporary  miraculous  interference  may  pos- 
sibly take  place,  for  special  purposes :  but  the  supposi- 
tion that  this  will  extend  to  a  permanent  alteration  of 
the  laws  of  nature,  is  absurd,  since  these  are  the  results 
of  boundless  benevolence,  unlimited  power,  and  omnis- 
cient wisdom ;  and,  therefore,  they  admit  of  no  improve- 
ment. 

The  laws  of  inorganic  nature  have  been  unchangeable, 
so  far  as  we  can  trace  them  :  and  although  many  old 
species  of  organic  beings  have  disappeared,  and  others 
succeeded  in  their  places,  no  species  was  ever  altered,  so 
far  as  we  can  find.  Now  as  the  same  Eternal  and  Im- 
mutable Creator,  w^ho  takes  no  second  thought,  and  all 
whose  works  are  perfect  of  their  kind,  will  forever  con- 


408  KNOWLEDGE  OF  FUTURITY.   [CHAP.  XXVII. 

tinue  to  rule  nature,  we  must  conclude  that  there  will  be 
no  change  of  the  natural  laws,  either  of  matter  or  of 
mind,  at  least  until  the  system  shall  be  dissolved  by  some 
great  upbreaking,  to  be  followed  by  another,  and  proba- 
bly similar,  system. 

That  the  present  system  of  the  world  will  continue  as 
we  now  behold  it,  for  an  immensely  long  period,  may  be 
proved  by  various  arguments,  of  which  the  following  are 
the  principal. 

1.  Astronomers  have   shown  that  the   solar   system 
would  go  on  forever,  as  it  now  does,  if  there  were  no  re- 
sisting medium,  and  God  did  not  interfere  miraculously. 
The  resisting  medium,  however,  appears  to  exist :  but 
there  are  proofs  that  its  influence  on  the  planets  will 
produce  no  important  change,  for  many  millions  of  years. 
It  is  further  found  that  the  Sun  revolves  round  some  dis- 
tant center,  at  a  rate  which  will  require  a  very  long  series 
of  ages  to  perform  a  single  revolution. 

Astronomy,  therefore,  leads  to  the  conclusion  that  the 
Earth  and  the  other  planets  will  continue  to  move,  and 
receive  light  and  heat  from  the  Sun,  as  they  now  do,  for 
many  millions  of  years.  The  immense  magnitude  of  the 
Sun,  and  the  extensive  chemical  and  electric  action  which 
must  be  incessantly  occurring  among  its  elements,  ob- 
viate any  fears  of  its  heat  or  light  failing,  during  all  that 
period :  and  the  effect  of  the  resisting  medium  may  pos- 
sibly be,  to  move  the  planets  very  slowly  nearer  the  Sun, 
as  these  gradually  diminish,  so  as  to  counterbalance  the 
deficiency,  until  the  time  of  the  final  catastrophe  has  ar- 
rived. 

2.  Geology  shows  that  the  Earth  has  been  the  resi- 
dence of  animals  incomparably  inferior  to  man,  for  count- 
less ages  before  he  existed :  and  it  is  a  manifest  absurd- 
ity to  suppose  that  it  was  to  be  miraculously  destroyed, 
a  few  thousand  years  after  it  became  gradually  fitted 
to  be  his  abode,  while  it  continued  to  be  as  suitable  as 
ever  for  his  residence. 

3.  The  preceding  argument  is  corroborated  by  observ- 
ing the  gradual  improvement  of  mankind,  from  early 
times,  and  the  absurdity  of  supposing  that  the  Earth 
should  be  destroyed  when  they  had  become  enlightened 
and  happy,  instead  of  being  the  reverse,  as  they  were  in 
early  times.     When  we  closely  observe  the  condition  of 
those  nations  who  stood  highest,  since  the  dawn  of  His- 


SEC.  2.]  ITS  SOURCES.  409 

tory,  during  the  successive  periods,  there  is  a  marked 
advance,  at  every  step,  since  those  times  when  the  most 
enlightened  nations  offered  human  sacrifices,  and  formal- 
ly worshiped  such  revolting  characters  as  Moloch  and 
Jupiter.  The  nature  of  truth  and  error,  and  the  charac- 
ter of  the  Most  High,  who  favors  the  advancement  of 
knowledge  and  virtue,  imply  that  the  course  of  improve- 
ment will  be  progressive,  until  mankind  shall  have  be- 
come what  they  were  designed  to  be,  and  the  future  shall 
vastly  excel  the  present. 

4.  If  we  consult  the  prophecies  of  Revelation,  we  are 
led  to  the  same  conclusion.  There  he  who  foresees  the 
end  from  the  beginning,  foretells  a  time  when  wars  will 
cease,  knowledge  be  universally  diffused,  and  all  men  be 
truly  religious,  moral  and  happy.*  Although  we  are  not 
distinctly  told  when  this  state  of  things  will  begin,  or 
how  long  it  will  last,  it  is  clearly  implied  that  the  time 
of  its  continuance  will  be  very  long.  Thus,  the  time  dur- 
ing which  the  pagans  were  to  continue  in  ignorance,  is 
called  a  moment ;  and  it  is  added  that  they  should  be 
visited  with  great  mercies,  and  everlasting  salvation.  So 
it  is  said  that  the  glorious  time  predicted  would  shortly 
arrive,  whence  it  follows  that  the  interval  is  of  no  account, 
compared  with  the  time  of  its  continuance.  Now  when 
it  is  observed  that  this  interval  extends  over  some  thou- 
sands of  years,  we  must  infer,  not  only  that  the  future  of 
man's  history  will  be  brighter  than  the  past,  but  that  it 
will  be  incomparably  longer. 

Thus  we  are  led,  by  different  lines  of  argument,  to  the 
conclusion  that  what  is  science  now,  will  continue  to  be 
so,  for  a  vast  period  of  time.  The  Almighty  has  endless 
duration  before  him  :  and  he  has  planned  the  present  ar- 
rangements of  the  universe  on  as  great  a  scale  with  re- 
spect to  their  continuance,  as  they  are  in  regard  to  their 
extent. 

Besides  the  statements  just  adverted  to,  Prophecy  fore- 
tells various  particular  events,  of  the  utmost  consequence. 
Of  these  the  general  judgement  of  all  mankind,  to  be  fol- 
lowed by  a  state  of  endless  weal  or  endless  woe,  is  con- 
spicuous for  its  paramount  importance,  and  forms  a  sub- 
ject which  every  one  should  examine  with  a  correspond- 
ing degree  of  attention  and  care. 

*  Isaiah,  Chapter  ii.,  1-4  ;  xi.,  1-9  ;  xxxv.,  liv. ;  Jeremiah,  xxxi., 
31-34  ;  Micah,  iv.,  1-4  ;  Revelation  of  John,  xxi.,  xxii.,  1-G. 

s 


410  KNOWLEDGE  OF  FUTURITY.   [CHAP.  XXVII. 

Particular  future  events  may  be  frequently  foreseen  by 
knowing  that  causes  operate  which  will  certainly  pro- 
duce them,  or  by  observing  present  indications  of  them. 
But  many  cases  of  this  kind  contain  some  uncertain  ele- 
ments, which  take  away  certainty,  and  render  the  future 
only  highly  probable.  The  degree  of  probability  may 
be  determined  by  means  of  the  principles  already  stated ; 
and  it  will  often  be  found  to  be  so  high  that  we  may 
safely  act  upon  it  as  if  it  were  a  certainty. 

With  regard  to  presentiments,  or  pretended  previous 
knowledge  of  future  events,  based  on  something  unde- 
fined, they  are  nothing  but  probable  inferences  from  pres- 
ent indications  or  feelings,  which  are  drawn  so  rapidly 
and  easily  that  the  process  is  overlooked  or  forgotten,  as 
is  habitually  done  in  the  case  of  other  guesses.  These 
frequently  turn  out  to  be  correct ;  and  such  instances  are 
then  noted,  and  adduced  as  proofs  of  the  truth  of  pre- 
sentiments. In  the  equally,  and  possibly  much  more, 
numerous  class  of  cases  in  which  they  turn  out  to  be 
false,  they  are  either  overlooked  or  ridiculed.  They  are 
not  essentially  different  from  the  conjectures  which  we 
are  incessantly  forming  regarding  futurity,  with  a  dis- 
tinct discernment  of  their  nature.  The  only  difference 
of  any  consequence  is,  that  presentiments  are  generally 
less  reliable,  because  they  are  more  frequently  based  on 
delusive  indications,  such  as  dreams,  reveries  or  omens. 

A  review  of  the  nature  and  extent  of  our  knowledge 
of  futurity  shows  that  it  is  adequate  to  our.  wants,  while 
it  falsifies  the  dogma  that  knowledge  may  be  dangerous. 
God  never  does  anything  which  he  desires  to  conceal. 
On  the  contrary,  he  desires  that  we  should  acquaint  our- 
selves with  his  works,  all  of  which  exhibit  the  high  and 
attractive  attributes  of  his  character ;  and  none  but  those 
who  read  them  aright,  fulfil  the  great  end  of  their  being. 
What  God  does  desire  to  conceal,  there  is  not  the  least 
danger  that  any  human  effort  will  ever  unfold. 


PART  V. 

OF  THE  RETENTION  OF  KNOWLEDGE. 


CHAPTER  XXVIII. 

OP  THE  RETENTION   OF   KNOWLEDGE   BY  SIMPLE  KEMEM- 
BKANCE. 

§  1.  GENERAL  LAWS  AND  RULES  OP  REMEMBRANCE. — Proper  appli- 
cation of  remembrance. — (1)  Law  of  Attention. — How  Attention 
may  be  excited. — Three  Rules  regarding  it. — Pernicious  Error,  and 
.how  it  may  be  avoided. — Why  an  Adept  often  remembers  better 
than  a  Tyro. — (2)  Law  of  Comprehension. — Importance  of  Appre- 
hensions.— (3)  Law  of  Generalization. — (4)  Law  of  repeated  Ex- 
aminations and  Reviews. —  Requisites. — When  mental  Reviews 
preferable  to  Apprehensional. — (5)  Law  of  Intervals. — Important 
Aids. — (6)  Law  of  Re-comprehension. — Its  Applications. — (7)  Law 
of  System  and  Arrangement. — Why  leading  Principles  should  bo 
first  attended  to. — Advantages  of  proper  Classification. — Principles 
of  Arrangement. — (8)  Hygienic  Law. — Agencies  which  injure  the 
Memory. — Why  it  is  particularly  affected  by  Dissipation. — Practi- 
cal Inference.— (9)  Law  of  the  Relation  of  Thoughts. — (10)  Law  of 
Recollection. — Where  it  applies,  and  how  its  Application  may  be 
facilitated. 

THE  power  of  remembrance  varies  greatly  in  different 
persons,  independently  of  culture :  but  the  power  of  re- 
membering permanently,  vividly,  and  without  confusion, 
depends  greatly  on  the  way  in  which  the  faculty  is  ap- 
plied ;  and  we  shall  consider  how  this  may  be  done  to 
the  best  advantage. 

»1.  The  influence  of  attention  on  remembrance  is  so 
striking  that  it  has  been  noticed  from  the  earliest  times. 
Things  which  we  have  seen  or  heard,  are  generally  soon 
fo*rgotten,  if  they  excited  little  attention  ;  and  whatever 
excites  strong  attention,  is  generally  remembered  perma- 
nently. This  holds  true  of  such  things  as  excite  strong 
emotion,  since  these  powerfully  attract  attention.  A 
scene  of  overwhelming  grief  or  ecstatic  joy,  for  instance, 
is  rarely  forgotten.  We  may  therefore  lay  it  down  as  .1 
law  of  remembrance,  that  whatever  strongly  excites  the  at- 
tention is  generally  remembered,  and  whatever  excites  lit- 
tle or  no  attention  is  generally  forgotten.  It  is  owing 
chiefly  to  the  various  directions  of  attention  that  several 
persons,  who  have  all  witnessed  the  very  same  scenes, 
remember  different  things ;  every  one  remembers  what 
forcibly  excited  his  attention,  and  forgets  the  rest. 


414       RETENTION  BY  REMEMBRANCE.  [CuAr.  XXVIII. 

In  order  to  excite  attention,  one  or  other  of  two  things 
is  necessary.  (1)  The  subject  must  spontaneously  excite 
a  strong  curiosity,  without  any  effort  on  our  parts,  as 
happens  when  we  view  a  thing  that  appears  very  strange 
and  striking,  or  read  a  very  remarkable  and  affecting 
narrative.  (2)  If  it  be  not  intrinsically  interesting,  it 
must  appear  to  have  a  bearing  on  something  which  we 
highly  value,  and  forgetfulness  or  ignorance  on  the  sub- 
ject must  be  thought  to  involve  serious  consequences. 
These  facts  suggest  the  three  following  rules  : 

(1)  Endeavor  to  obtain  a  knowledge  of  the  elements  of 
a  subject,  and  fix  them  firmly  in  the  memory,  during  the 
first  study :  for  then  it  possesses  the  charm  of  novelty, 
which  is  favorable  to  close  attention.     If  we  follow  a 
different  course,  and  skim  over  the  surface  at  first,  it  be- 
comes more  difficult  to  remember  the  subject  afterwards, 
since  the  attention  is  much  more  apt  to  wander  from  the 
point  under  consideration: 

(2)  If  the  subject  possesses  no  intrinsic  novelty,  we 
should  carefully  examine  its  bearings,  until  we  clearly 
see  its  importance,  and  its  connection  with  the  future. 
When  we  distinctly  perceive  that  much  depends  on  our 
understanding  and  remembering  a  subject,  there  is  little 
danger  that  the  attention  will  flag,  however  uninviting  it 
may  be  in  itself.     This  is  proved  by  the  alacrity  with 
which  mankind  do  many  things,  much  more  disagree- 
able than  to  study  attentively  any  subject  which  is  worth 
studying,  solely  for  the  sake  of  earning  a  little  money,  or 
perhaps  gratifying  some  favorite  desire.     The  rewards 
of  the  explorer  of  truth  are  richer  and  surer ;  and,  there- 
fore, it  is  only  necessary  that  he  should  understand  their 
value,  in  order  to  work  with  attentive  eagerness  in  the 
pursuit. 

(3)  Overlook  trifling  details,  or  irrelevant  matter  ;  and 
attend  only  to  what  is  worth  remembering,  and  capable 
of  being  remembered  permanently .     For  the  attention  is 
distracted,  and  remembrance  consequently  weakened,  by 
being  drawn  to  many  objects  simultaneously.    We  should 
guard  against  the  pernicious  error  of  burdening  and  con- 
fusing the  Memory  by  attending  to  many  things  at  once, 
or  by  cramming  it  with  a  multitude  of  facts  which  are 
not  worth  remembering,  or  which  are  sure  to  be  speed- 
ily forgotten.     The  cognitions  embraced  in  all  depart- 
ments of  knowledge  are  far  too  numerous  to  be  retained 


SEC.  1.]          GENERAL  LAWS  AND  RULES.  415 

by  any  Memory ;  and  there  are  many  truths  the  recol- 
lection of  which  tends  rather  to  perplex  and  mislead  the 
Judgement  than  to  answer  any  good  purpose.  The  con- 
sideration of  them  leads  us  to  confound  matters  of  no 
consequence  with  what  is  material,  and  to  withdraw  the 
attention  from  the  essential  parts  of  the  subject. 

In  order  to  avoid  such  results,  we  should  beware  of 
paying  any  attention  to  things  which  were  better  over- 
looked, for  the  time  being,  and  of  attempting  to  commit 
to  memory  what  is  not  worth  remembering,  or  what  can- 
not be  remembered  for  any  length  of  time.  Where  some 
important  object  calls  our  attention  to  anything  of  this 
kind,  we  should  pay  no  more  attention  to  it  than  the  ob- 
ject requires. 

We  may  now  understand  why  a  person  already  famil- 
iar with  a  subject  remembers  new  discoveries  regarding 
it  so  much  better  than  others.  His  previous  knowledge 
excites  strong  attention,  on  account  of  the  interest  he 
feels  in  it,  while  it  guides  his  attention  to  those  things 
that  are  most  important.  Hence,  when  we  have  once 
mastered  the  elements  of  a  science,  our  future  attain- 
ments in  it  are  acquired  and  retained  with  unusual  fa- 
cility. 

2.  Memory  is  aided  by  clearness  and  distinctness  of 
the  original  comprehensions.    As  ideas  are  copies  of  their 
prototypes,  any  obscurity  or  vagueness  in  the  latter  nec- 
essarily attaches  to  the  former,  and  leads  to  confusion 
and  forgetfulness.     Hence  clearness  and  distinctness  of 
comprehension  are  favorable   to  lasting  remembrance. 
Thus   close   attention  to   comprehensions  aids  remem- 
brance as  well  as  a  right  understanding  of  the  subject  at 
first. 

As  we  can  seldom  form,  from  mere  descriptions,  con- 
ceptions so  vivid  as  our  own  comprehensions  of  the  ob- 
jects, Memory  is  aided  by  subjecting  to  our  apprehension 
either  the  very  things  to  be  remembered  or  accurate  rep- 
resentations of  them.  Thus,  we  can  remember  a  scene 
which  we  have  witnessed  much  better  than  one  of  which 
we  merely  read  a  description  ;  and  we  remember  the  po- 
sitions of  objects  in  a  country  much  better  by  surveying 
a  map  of  it,  than  by  simply  reading  a  description  of  those 
positions. 

3.  As  a  general  proposition  includes  many  particular 
ones,  and  yet  is  remembered  as  easily  as  one  of  the  lat- 


410       RETENTION  BY  REMEMBRANCE.  [CHAP.  XXVIII. 

ter,  Memory  is  aided  by  the  extension  of  generalization. 
As  inductions  are  wider  than  empiricisms,  and  at  the 
same  time  more  free  from  details,  they  assist  memory  as 
much  as  they  extend  knowledge ;  and  this  is  probably 
one  reason  why  mankind  have  been  so  prone,  in  all  ages, 
to  assume  mere  empiricisms  for  scientific  generaliza- 
tions. 

4.  Remembrance  is  rendered  more  distinct  and  perma- 
nent by  repeated  examinations  and  reviews.     This  truth 
is  learned  at  a  very  early  period  of  life ;  and  the  practice 
which  it  suggests  is  one  of  the  most  common  means  of 
committing  to  memory  pieces  of  composition.     Yet  the 
value  of  mere  repetition  is  generally  overestimated.     In 
order  to  render  it  effectual,  it  must  be  done  deliberately 
and  attentively :  otherwise  the  whole  is  apt  to  be  soon 
forgotten,  as  when  we  learn  a  string  of  words  in  an  un- 
known language.     It  is  further  observable  that  a  close 
mental  review  of  a  subject,  soon  after  the  original  com- 
prehension, without  appealing  to  any  external  object  ex- 
cept when  the  Memory  is  at  fault,  generally  aids  perma- 
nent remembrance  more  than  a  re-apprehending  of  the 
objects.     Thus,  we  remember  the  contents  of  a  book 
much  better  by  reviewing  it  mentally  after  perusal,  and 
referring  to  the  book  only  when  we  are  at  a  loss,  than  if 
we  were  simply  to  read  it  over  a  second  time. 

The  cause  of  this  is  probably  the  greater  degree  of  at- 
tention required  to  recollect  than  to  re-apprehend  an  ob- 
ject. In  the  latter  case  the  mind  may  be,  in  a  great 
measure,  passive,  and  wander  incessantly  to  other  mat- 
ters, whereas,  in  the  former,  it  is  necessarily  active  and 
attentive ;  otherwise  the  process  could  not  be  performed. 
But  where  a  long  time  has  elapsed  since  the  original  com- 
prehension, the  case  may  be  otherwise,  as  the  ideas  may 
then  have  become  indistinct,  or  been  wholly  lost. 

5.  A  thing  is  committed  to  memory  more  easily  by  re- 
peating and  reviewing  at  short  intervals,  than  by  the 
same  number  of  exertions,  at  long  intervals.     In  the  lat- 
ter case,  one  impression  is,  in  a  great  measure,  lost  be- 
fore another  succeeds,  whereas,  in  the  former  case,  the 
succeeding  impression  seems  to  strengthen  the  former ; 
and  if  the  process  is  properly  repeated  several  times,  it 
may  produce  permanent  remembrance,  while  the  same 
number  of  operations,  repeated  at  Jong  intervals,  might 
wholly  fail  to  do  so. 


SEC.  1.]  GENERAL  LAWS  AND  RULES.  417 

When  a  subject  is  so  extensive  that  frequent  reviews 
of  it  are  impracticable,  we  may  draw  up  summaries  of 
the  most  important  parts,  showing  their  relations  to  eacli 
other,  and  confine  our  reviews  to  these.  In  such  cases 
abridgements  and  tabular  synopses  are  of  great  use,  as 
well  as  conversations  on  the  subject  with  persons  who 
know  it  well,  or  feel  much  interested  in  it. 

6.  Fading  similitudes  are  rendered  precise  and  vivid 
by  re-comprehending  their  prototypes.     Thus,  if  we  at- 
tempt to  recall  the  idea  of  a  friend,  whom  we  have  not 
seen  for  many  years,  we  may  find  that  it  is  vague  and  in- 
distinct :  but  if  he  come  in  sight,  we  may  possibly  recog- 
nize the  smallest  peculiarity  in  his  appearance,  the  idea 
being  now  rendered  very  clear  and  accurate.*  Although 
this  effect  is  partly  temporary,  it  is  by  no  means  wholly 
so :  for  the  idea  continues  permanently  more  distinct  and 
vivid  than  before,  especially  if  we  have  viewed  the  pro- 
totype with  close  attention.     By  a  proper  application  of 
this  principle,  the  attainments  of  early  life  may  be,  in  a 
great  measure,  preserved  through  all  our  later  years. 

7.  Memory  is  aided  l>y  a  systematic  course  of  learn- 
ing, and  a  proper  arrangement  of  our  acquisitions.     In 
all  subjects,  there  is  a  certain  relation  between  one  part 
and  another,  which  may  be  made  subservient  to  the  re- 
membrance of  both.     In  order  to  this,  we  have  only  to 
trace  and  attentively  mark  these  relations ;  and  then  the 
idea  of  the  one  will  recall  that  of  the  other.     But  this 
will  not  generally  happen,  unless  we  examine  the  vari- 
ous parts  of  a  subject,  in  regular  succession,  according  to 
their  relations :  for  if  we  pursue  a  different  course,  the 
ideas  of  the  various  parts  will  be  confused  in  our  minds, 
and  the  connecting  bond  will  be  wanting. 

The  remembrance  of  a  leading  principle  will  generally 
secure  that  of  its  subordinate  truths  or  consequences, 
provided  we  first  learn  the  former,  then  proceed  to  the 
latter,  and  mark  the  relations  in  which  they  stand  to 
each  other.  A  proper  system  of  classification  will  ena- 
ble us  to  do  this  with  little  difficulty,  as  it  renders  the 
relations  of  the  various  parts  to  each  other  easy  to  be 
discovered. 

In  arranging  our  acquisitions  we  should  be  guided  by 
the  ordinary  principles  of  classification,  already  discuss- 
ed ;  and  when  we  have  once  made  an  arrangement,  on 
particular  principles,  we  should  not  change  it  afterwards, 

S  2 


418       RETENTION  BY  REMEMBRANCE.  [CHAP.  XXVIII, 

unless  for  some  urgent  reason,  as  the  change  confuses  the 
Memory. 

8.  The  Memory  is  much  influenced  by  the  state  of  the 
nervous  system.     This  is  frequently  observable  in  severe 
injuries  of  the  head,  and  in  several  diseases  affecting  the 
brain.    A  wound  in  the  head  has  sometimes  led  to  a  per- 
son's forgetting  a  great  part  of  his  language,  and  much 
of  his  knowledge  of  other  things.     So  everything  which 
produces  a  languid  or  diseased  state  of  the  blood,  weak- 
ens the  Memory,  owing  to  the  injurious  influence  exert- 
ed on  the  brain.     That  this  is  not  owing  merely  to  dis- 
tracting the  attention,  appears  from  its  existing  where 
there  is  no  such  distraction,  although,  in  many  cases, 
this  difficulty  also  is  added. 

Dissipated  habits  affect  memory  directly  by  their  dele- 
terious influence  on  the  blood,  and  consequently  on  the 
brain,  while  they  affect  it  indirectly  by  destroying  the 
power  of  close  and  continued  attention.  Hence  the  reg- 
ular and  temperate  habits  which  are  requisite  for  gener- 
al vigor  of  intellect,  are  equally  necessary  for  faithful  and 
permanent  remembrance. 

What  was  formerly  said  regarding  the  propriety  of 
attending  to  the  laws  of  health,  during  investigation,  is 
equally  applicable  to  this  subject,  because  every  serious 
violation  of  these  laws  injures  the  brain,  more  or  less, 
and  thus  impairs  the  power  of  clear  and  vivid  remem- 
brance. 

9.  Certain  thoughts  are  so  related  to  each  other  that 
thinking  one  leads  us  to  think  the  other.     This  law  op- 
erates so  incessantly  that  it  can  hardly  escape  the  notice 
of  anybody  ;  and,  as  we  have  already  seen,  Memory  con- 
sists wholly  in  the  faculty  of  thus  passing  from  one  thought 
to  another,  whence  it  appears  that  direct  remembrance  is 
wholly  dependent  on  the  relations  of  thoughts. 

10.  Recollection  is  exercised  by  recalling  tlie  thoughts 
to  which  the  one  sought  is  related.     It  frequently  hap- 
pens that,  although  we  have  no  direct  remembrance  of 
the  thing  sought,  we  know  that  it  is  related  to  some- 
thing; which  is  remembered  directly.    Thus,  we  may  have 
no  direct  remembrance  of  the  time  when  we  last  saw  a 
particular  friend ;  but  we  may  remember  it  was  at  such 
a  place ;  and  we  may  then  directly  remember  the  time 
when  we  were  there.     So  the  time  may  often  enable  us 
to  recollect  the  place  where  something  happened. 


SEC.  2.]  RELATIONS  OF  THOUGHTS.  419 

In  order  to  facilitate  the  application  of  this  law,  we 
should  note  to  what  familiar  thought  the  thing  to  be  rec- 
ollected is  related :  for  by  this  means  the  former  will  be 
apt  to  be  remembered  when  we  are  trying  to  recollect 
the  latter. 

§  2.  Or  THE  RELATIONS  OF  THOUGHTS. — Two  kinds  of  Relations.— ~ 
Laws  of  Natural  Relation. — (1)  Law  of  Contiguity  and  Succession. 
— Usual  Course  of  the  Similitudes. — Rule  based  on  this  Law. — 
Modifications. — How  the  Relation  may  be  strengthened. — (2)  Law 
of  Resemblance.  —Analogies. — Requisites  to  render  it  available. — 
How  aided. — (3)  Law  of  Emotions. — Its  Operation. — Rule  based 
on  it. — Advantage  attending  it. — Important  Difference. — (4)  Law 
of  Contraries. — Why  less  reliable  than  the  preceding. — Arbitrary 
Relations. — Mnemotechny. — Harmony  of  Laws. — How  new  Ac- 
quisitions strengthen  Remembrance. — Different  Effects  of  Exercise 
on  Memory. — Evils  of  Cramming. — Important  Rule. — Means  of 
widening  the  Range  of  Relations. — Why  Sight  generally  affects  us 
more  than  mere  Description. — Disadvantages  of  visible  Representa- 
tions.— Effects  of  Desires. — Why  some  things  are  well  remembered 
and  others  readily  forgotten. 

Some  thoughts  are  so  related  or  connected  that  one 
excites  the  other  without  any  effort.  Thus,  the  sight  of 
one  thing  leads  us  to  think  of  another  which  looks  very 
like  it ;  and  when  we  think  of  a  remarkable  scene  that 
we  witnessed,  we  think  of  what  occurred.  Such  connec- 
tions may  be  termed  natural.  In  other  cases,  a  desire 
to  remember  a  particular  thing  leads  us  to  search  for 
some  familiar  thought  with  which  we  may  connect  it,  by 
a  voluntary  effort.  Thus,  if  we  know  when  Alexander 
the  Great  lived,  we  may  remember  when  the  emperor 
Constantine  lived,  by  noting  that  he  was  just  as  long 
after  the  birth  of  Christ  as  Alexander  was  before  it. 
Such  relations  may  be  termed  arbitrary  or  artificial,  as 
the  thoughts  attempted  to  be  connected  are  not  natural- 
ly related. 

The  following  are  the  principal  laws  of  the  natural  re- 
lations of  thoughts. 

1.  The  law  of  contiguity  and  succession,  which  may 
be  expressed  thus:  the  similitudes  of  contemporaneous 
thoughts  arise  simultaneously,  and,  if  not  interfered  icith, 
in  the  order  of  their  prototypes.  If  we  think,  for  exam- 
ple, of  a  certain  place  which  we  have  lately  visited,  the 
ideas  of  the  things  seen  and  heard  there  arise  at  once, 
with  the  iitmost  rapidity,  and  also  the  similitudes  of  all 
our  thoughts  at  that  time,  so  that  we  know  what  emo- 


420      RETENTION  BY  REMEMBRANCE.  [CHAP.  XXVIII. 

tions  we  felt,  what  intellectual  processes  we  performed, 
and  what  conclusions  we  deduced.  Then  the  similitudes 
of  subsequent  thoughts  arise,  in  the  order  of  time,  down 
to  the  present  moment,  if  no  volitions  or  other  laws  in- 
terfere. But  a  slight  effort  of  the  will  may  alter,  or  even 
reverse,  the  process,  and  lead  us  backward,  through  pre- 
vious thoughts,  or  some  resemblance  or  contrast  between 
something  in  the  series  and  some  other  thought,  suggest- 
ed either  by  some  external  object  or  by  our  own  feelings, 
may  lead  the  Memory  into  a  totally  different  channel,  so 
that,  in  the  course  of  a  few  seconds,  our  thoughts  may 
possibly  have  roved  over  the  whole  creation. 

This  law  suggests  the  rule  that  our  thougJits  should  be 
concentrated  on  a  few  objects,  where  we  desire  that  the  re- 
membrance of  them  should  be  clear  and  permanent.  For, 
if  we  act  otherwise,  so  many  similitudes  arise  afterwards, 
when  we  think  of  them,  that  the  mind  is  apt  to  be  con- 
fused, and  led  off  from  the  path  which  we  desire  that  it 
should  hold.  Hence  many  studies  at  one  time  are  unfa- 
vorable to  remembrance,  independently  of  the  bad  effects 
of  distracted  attention  while  we  are  learning. 

The  law  of  antecedent  and  consequent  is  only  a  partic- 
ular case  of  that  of  contiguity  and  succession,  these  al- 
ways standing  to  each  other  in  that  relation.  A  special 
modification  of  this  case  is  that  of  cause  and  effect,  which 
are  always  related  as  antecedent  and  consequent.  An- 
other frequent  modification  is,  the  law  o>i  premise  and  in- 
ference, which  are  always  contiguous  in  thought,  although 
they  may  be  separated  in  expression. 

These  relations  are  strengthened  by  other  agencies, 
such  as  the  suggestions  of  the  Judgement,  influenced  by 
the  desire  of  securing  one  object  or  avoiding  another, 
and  the  easy  transition  from  premise  to  inference,  on  ac- 
count of  the  self-evident  connection.  Thus,  when  we 
witness  a  disastrous  effect,  the  desire  of  removing  it 
leads  us  to  think  of  the  cause,  and  so  recalls  anything 
which  we  may  have  formerly  observed,  bearing  on  this 
point.  So,  when  we  witness  a  powerful  cause  in  opera- 
tion, we  are  reminded  of  what  we  may  have  formerly  ob- 
served regarding  the  effects  of  the  same  or  similar  agen- 
cies. Hence  things  connected  as  cause  and  effect  recall 
each  other  more  readily  than  mere  antecedent  and  con- 
sequent. In  the  same  way,  when  we  think  of  premises, 
the  inferences  are  apt  to  come  into  view,  independent- 


SEC.  2.]  RELATIONS  OF  THOUGHTS.  421 

ly  of  previous  reasoning;  and  hence  these  are  readily 
brought  to  remembrance. 

To  the  same  general  law  belong  various  other  laws, 
which  are  evidently  nothing  but  modifications  of  it,  such 
as  that  of  means  and  end,  name  and  object,  ichole  and 
part,  to  all  of  which  the  remarks  made  in  the  preceding 
paragraph  are  applicable. 

2.  The  law  of  resemblance,  which  may  be  expressed 
thus :  one  thought  recalls  similar  thoughts.     Thus,  when 
we  see  an  object  which  looks  very  like  one  that  is  famil- 
iar to  us,  we  immediately  think  of  the  latter.     So  when 
we  hear  a  musical  air,  like  one  which  we  admire,  the  idea 
of  the  latter  immediately  arises  ;  and  if  a  foreign  field  ex- 
hales a  fragrance  like  those  of  our  native  place,  we  im- 
mediately think  of  the  latter,  and  the  scenes  of  child- 
hood.    One  of  the  most  common  exercises  of  this  law  is 
in  recognition,  where  the  comprehension  of  the  proto- 
type recalls  the  similitude,  as  formerly  stated,  and  thus 
we  recognize  and  identify  many  objects  formerly  appre- 
hended.    Although  apprehensions  recall  ideas  more  viv- 
idly than   similitudes   do,  yet  the   connection  extends 
equally  to  all. 

This  law  extends  to  analogies,  as  well  as  to  direct  re- 
semblances ;  and  some  of  the  most  important  applica- 
tions of  it  are  based  on  this  property,  as  the  success  of  a 
discoverer  or  inventor  frequently  depends  on  some  anal- 
ogy, suggested  by  what  is  already  well  known. 

In  order  t©  render  the  law  of  resemblance  sufficiently 
available,  the  points  of  similarity  must  be  perceived ; 
and  the  more  numerous  these  appear,  or,  in  other  words, 
the  more  complete  we  observe  the  likeness  to  be,  the 
more  readily  and  surely  will  the  one  object  recall  the 
other.  As  the  closest  resemblances  are  not  always  ap- 
parent at  first  sight,  the  operation  of  this  law  will  be  fa- 
cilitated and  extended  by  our  knowing  the  recondite,  as 
well  as  the  manifest,  points  of  similarity  between  two  ob- 
jects ;  and  hence  remembrance  is  aided  by  marking  the 
former  as  well  as  the  latter. 

3.  The  law  of  emotions,  which  may  be  expressed  thus  : 
things  directly  connected  icith  powerful  emotions,  are  re- 
called with  unusual  facility .     Let  a  person,  for  example, 
attend  to  his  ordinary  business,  just  after  hearing  of  the 
death  of  a  beloved  friend :  his  thoughts  may,  for  the  mo- 
ment, be  wholly  occupied  with  his  business ;  but,  speed- 


422       RETENTION  BY  REMEMBRANCE.  [€HAP.  XXVIII. 

ily,  and  without  any  external  cause,  he  thinks  of  the 
deceased:  again  lie  banishes  the  painful  thought,  and 
again  it  soon  intrudes.  On  the  other  hand,  a  person 
who  has  just  heard  a  very  joyful  piece  of  news,  ever  and 
anon  returns  to  the  agreeable  theme. 

.Owing  to  the  operation  of  this  law,  which  acts  with 
great  force  and  constancy,  things  which  have  once  ex- 
cited strong  emotions  are  apt  to  be  easily  recalled  ever 
afterwards,  independently  of  the  greater  degree  of  atten- 
tion which  they  may  have  excited  in  the  first  instance. 
Hence  we  should,  if  possible,  place  those  things  which  ice 
desire  to  remember,  in  such  a  light  that  they  will  power- 
fully affect  our  sensibilities.  If  we  do  so,  there  is  little 
danger  that  they  will  be  afterwards  forgotten. 

A  great  advantage  attending  the  operation  of  this  law 
is,  that  those  subjects  which  are  most  important  excite 
the  deepest  emotions,  when  things  are  well  understood 
and  seen  in  their  true  bearings.  The  strong  emotions 
requisite  to  permanent  remembrance  are  by  no  means 
unfavorable  to  the  acquisition  of  truth :  for  they  rather 
secure  than  distract  attention,  and  generally  become 
strongest  after  the  investigation  has  been  concluded,  as 
the  very  uncertainty  of  a  proposition  tends  to  moderate 
emotion,  until  its  real  nature  has  been  ascertained. 

Those  violent  and  transient  emotions  termed $>assions, 
differ  widely  from  the  deep  and  permanent  feelings  which 
arise  from  taking  a  calm  and  extensive  survey  of  an  im- 
portant subject.  The  former  always  spring  from  exag- 
gerated, narrow,  or  one-sided  views  of  a  subject;  and 
they  are  liable  to  occur  only  when  we  consider  a  subject 
of  real  or  supposed  importance,  which  we  have  never 
rightly  understood  or  seen  in  its  true  light.  They  are 
decidedly  unfavorable  to  the  acquisition  or  retention  of 
truth,  since  their  violence  concentrates  the  attention  too 
much  on  certain  points,  and  thus  leads  to  others  being 
viewed  hastily  or  altogether  overlooked.  But  those  per- 
manent emotions  are  not  so  violent  as  to  produce  any 
such  results ;  and  they  generally  arise  from  views  essen- 
tially correct. 

4.  The  law  of  contraries,  according  to  which  thinking 
of  a  thing  recalls  its  contrary.  When  we  are  oppressed 
with  the  heat  of  summer,  we  are  reminded  of  the  cold 
of  whiter ;  and  when  we  see  a  desert  waste,  we  are  apt 
to  think  of  a  fertile  land.  Here,  however,  the  connection 


SEC.  2.]  RELATIONS  OF  THOUGHTS.  423 

does  not  seem  to  be  primary  and  immediate ;  but  some 
emotion  or  sensation  suggests  its  contrary,  by  some  in- 
termediate steps.  The  uneasy  sensation  of  heat,  for  ex- 
ample, leads  us  to  desire  cold ;  and  the  sight  of  the  des- 
ert leads  us  to  think  of  the  cause  of  its  barrenness, 
whence  we  pass,  by  a  natural  transition,  to  the  fertile 
region.  - 

Owing  to  its  dependent  nature,  this  law  is  less  con- 
stant and  reliable  than  the  others,  and  of  comparatively 
little  value  in  aiding  memory. 

Arbitrary  relations  are  frequently  useful  for  temporary 
purposes:  but  they  are  seldom  of  much  use  in  aiding 
permanent  remembrance,  as  the  relation  selected  is  very 
apt  to  be  forgotten.  Rules  for  the  formation  of  such  re- 
lations arc  of  no  value  whatever,  since  that  which  first 
offers  is  generally  the  best  for  effecting  the  temporary 
recollection  for  which  alone  these  relations  are  of  any 
use,  as  it  is  the  one  which  will  most  readily  suggest  it- 
self when  required.  Systems  of  Mnemotechny  are  appli- 
cable chiefly  to  dates  and  numbers :  and  even  these  can 
generally  be  remembered  more  effectually  by  other 
means. 

Those  relations  which  are  aided  by  extraneous  sugges- 
tions, like  that  of  cause  and  effect,  or  premise  and  infer- 
ence, are  more  reliable  than  such  as  depend  solely  upon 
the  intrinsic  power  of  relation,  since  the  suggestions  co- 
operate in  producing  the  desired  result.  Hence  relations 
based  on  some  real  likeness  or  natural  connection  of  the 
things  related,  are  more  effectual  than  such  as  depend  on 
fancied  resemblances  or  casual  juxtaposition  ;  and,  there- 
fore, we  should  attend  chiefly  to  the  former.  Thus,  a 
public  speaker  may  remember  the  different  parts  of  his 
discourse  much  better  by  giving  it  a  logical  form,  and 
marking  the  mutual  connection  and  dependence  of  its 
several  parts,  than  by  attempting  to  connect  them  with 
the  various  rooms  of  a  house,  as  was  frequently  done  by 
some  of  the  ancient  orators. 

In  noting  resemblances,  we  should  attend  primarily  to 
the  most  important,  or  those  which  determine  the  gener- 
al character  of  the  objects,  and  attend  to  minor  points 
of  similarity  afterwards,  since  the  former  are  most  easily 
remembered,  and  suggest  the  latter.  Hence  the  laws  of 
remembrance  here  harmonize  with  those  of  original  ac- 
quisition. 


424       RETENTION  BY  REMEMBRANCE.  [CHAP.  XXVIII. 

Since  every  observed  relation  of  one  thing  to  another 
forms  a  connection,  remembrance  is  strengthened  as  the 
number  of  such  relations  increases :  and  hence,  as  long 
as  new  acquisitions  multiply  such  connections,  the  more 
we  know,  the  better  we  remember.  Such  additions  to 
our  knowledge  multiply  the  bands  that  unite  its  various 
parts  in  the  Memory,  while  they  are  themselves  associ- 
ated with  so  many  of  the  old  elements  that  they  are  in 
little  danger  of  being  forgotten.  A  new  discovery  often 
unites  into  one  whole  many  elements  of  knowledge  hith- 
erto apparently  unconnected.  It  is  thus  that  Memory  is 
apparently  strengthened  by  exercise :  for  if  we  merely 
load  it  with  unconnected  or  unrelated  facts,  it  becomes 
confused  and  weakened,  instead  of  being  strengthened. 
We  should,  therefore,  never  attempt  to  burden  it  with 
unimportant  details,  which  are  not  worth  remembering. 

In  order  to  strengthen  the  Memory,  we  should  mark 
the  various  relations  which  the  thing  to  be  remembered 
beam  to  several  others  that  are  well  knoicn,  and  avoid  un- 
important and  unconnected  details.  By  this  means  it 
will  become  associated  with  all  these,  so  that  it  may  be 
recollected  by  thinking  of  any  of  them.  Consequently 
the  practice  of  observing  the  relations  of  new  acquisi- 
tions to  our  previous  attainments,  is  as  favorable  to  re- 
membrance as  it  is  to  discovery  and  invention. 

A  good  means  of  widening  the  range  of  known  rela- 
tions is,  to  observe  a  thing  in  as  many  different  ways  as 
circumstances  will  permit :  for  it  may  thus  become  asso- 
ciated with  the  ideas  of  the  different  senses ;  ancl  if  one 
fail  or  hesitate,  the  others  may  still  avail.  Thus,  in  the 
case  of  chemical  or  mineral  specimens,  we  may  see,  feel, 
smell  and  taste  the  substance  whose  properties  we  desire 
to  remember. 

Owing  to  the  comparative  feebleness  of  the  power  of 
Conception,  in  the  great  majority  of  mankind,  things  ad- 
dressed to  the  eye  produce  a  more  permanent  impression 
than  mere  descriptions:  but  the  narrow  limits  of  ocular 
representations  render  the  latter  generally  indispensable ; 
and,  in  many  of  the  most  important  subjects,  the  former 
are  unavailable,  as  no  accurate  representation  can  be 
given.  Thus,  the  best  representations  of  the  solar  sys- 
tem are  so  defective  that  the  notions  which  they  convey 
are  extremely  erroneous,  unless  they  are  corrected  by 
the  aid  of  description  and  conception,  while,  in  the  case 


SEC.  1.]  GENERAL  OBSERVATIONS.  425 

of  purely  mental  objects,  such  representations  are  often 
worse  than  useless. 

Although  desires  and  volitions  are  incessantly  chang- 
ing the  previous  currents  of  our  thoughts,  and  substitu- 
ting others,  yet  every  train  of  thought  strictly  obeys  the 
laws  of  relation :  and  hence  these  ever-varying  currents 
may  recall  any  former  act  or  thought  of  our  lives  which 
is  connected  with  others.  Things  much  valued  are  well 
remembered,  not  only  on  account  of  the  attention  which 
they  excite  when  they  are  thought  of,  but  also  because 
we  voluntarily  search  for  them,  and  dwell  on  them  when 
they  are  presented  to  view,  whence  they  become  strong- 
ly connected  with  many  other  things.  For  similar  rea- 
sons, things  little  valued  are  apt  to  be  totally  forgotten, 
except  where  they  have  severely  pained  our  feelings. 


CHAPTER  XXIX. 

OF   THE    EETENTION    OP   KNOWLEDGE    BY   MEANS.   OF   EX- 
TERNAL  SIGNS. 

§  1.  OF  EXTERNAL  SIGNS  IN  GENERAL. — Advantages  of  External 
Signs. — Various  Modes  of  their  Operation. — Monuments  and  Com- 
memorations.— Advantages  and  Disadvantages  of  direct  Likeness- 
es, Symbols,  and  Phonetic  Representations. — Best  Course. 

THE  extent  of  human  attainments  is  such  that,  after 
employing  all  the  aids  of  Memory  discussed  in  the  pre- 
ceding chapter,  external  signs  are  requisite,  in  order  to 
secure  .the  largest  and  most  important  portions  of  knowl- 
edge. For,  although  similitudes  represent  the  things  to 
be  remembered,  without  any  external  sign,  yet  they  are 
liable  to  be  forgotten ;  and  as  they  pass  away  with  the 
individual,  they  cannot  make  knowledge  permanent  in  a 
community. 

External  signs  operate  in  various  ways.  When  a  per- 
son ties  a  string  on  his  little  finger,  or  a  knot  on  his  hand- 
kerchief, the  sight  of  the  unusual  object  recalls  its  origin, 
evidently  in  virtue  of  the  law  of  cause  and  effect.  Of 
the  same  kind  are  monuments  and  periodic  commemora- 
tions. These  preserve  a  knowledge  of  occurrences,  be- 
cause they  excite  curiosity  and  inquiries  regarding  their 
origin,  so  that  every  generation  learn  the  cause  from  their 
predecessors,  and  afterwards  communicate  it  to  those 


426      RETENTION  BY  EXTERNAL  SIGNS.  [CHAP.  XXIX. 

who  succeed.  So  the  boundaries  of  land  are  frequently 
known  from  posts  or  stones  fixed  in  the  ground.  But 
such  devices,  at  the  best,  preserve  only  the  remembrance 
of  the  principal-facts  or  events :  and,  in  order  to  retain  a 
knowledge  of  details,  we  must  have  recourse  to  more  va- 
ried and  unequivocal  signs. 

Direct  likenesses  possess  over  all  other  mnemonic  signs 
the  advantages  of  representing  the  very  things  to  be  per- 
petuated, in  a  lively  and  striking  manner,  placing  a  scene 
before  the  eye  without  calling  in  the  aid  of  Conception, 
and  exhibiting  some  peculiarities  which  description  can- 
not so  well  convey.  They  give  us  more  accurate  notions, 
in  many  instances,  than  can  possibly  be  obtained  from 
mere  descriptions,  while  they  render  similitudes  more 
precise  and  vivid,  like  re-comprehending  their  proto- 
types, so  that,  when  very  accurate  and  complete,  their 
effects  are  not  much  inferior,  in  these  respects,  to  the  lat- 
ter process. 

Symbolic  representations  are  employed  chiefly  where 
direct  likenesses  are  inadmissible,  owing  to  the  thing 
which  it  is  designed  to  perpetuate  being  invisible,  or  in- 
capable of  direct  pictorial  representation :  and  they  some- 
times set  this  forth  more  forcibly  and  comprehensibly 
than  verbal  descriptions,  just  as  figurative  expressions 
sometimes  portray  an  occurrence  more  clearly  and  strik- 
ingly than  those  which  are  literally  true. 

Yet  much  is  still  requisite  in  which  those  devices 
wholly  fail.  Direct  likenesses  can  generally  represent 
only  a  small  portion  of  what  is  visible,  while  the  invisi- 
ble, which  is  usually  the  most  important  part  of  tjie  sub- 
ject, cannot  be  thus  represented  at  all.  The  range  of 
symbolic  likenesses,  again,  is  very  narrow,  unless  their 
number  is  multiplied  so  as  to  overburden  the  Memory, 
and  render  their  import  very  liable  to  be  misunderstood 
or  forgotten.  Hence  the  value  of  writing  or  printing, 
which,  by  means  of  characters  denoting  its  elementary 
sounds,  perfectly  expresses  language,  so  that  we  can  ac- 
curately and  easily  retain  whatever  can  be  spoken. 

Writing  furnishes  the  means  of  expressing  all  human 
thought  with  great  precision  and  the  utmost  generalit}', 
while  the  number  of  characters  required  is  so  small  that 
the  Memory  need  never  be  burdened  in  remembering 
them.  It  also*  removes  the  vagueness  and  uncertainty 
which  frequently  attach  to  all  other  methods,  when  we 


SEC.  2.]  WKITING.  42*7 

attempt  to  express  details,  or  a  continuous  chain  of 
events  or  thoughts ;  and  it  prevents  the  numerous  mis- 
takes and  total  loss  of  knowledge  incident  to  relying  on 
simple  remembrance.  Moreover,  as  the  composition  can 
be  rewritten  or  reprinted  without  limit,  it  can  be  hand- 
.ed  down  unchanged  through  countless  ages.  Thus  writ- 
ing preserves  the  knowledge  of  past  ages,  and  enables 
those  of  succeeding  times  to  use  or  improve  upon  the  at- 
tainments of  their  predecessors. 

As  every  class  of  signs  possesses  advantages  and  dis- 
advantages, the  best  method  is  that  which  combines  the 
advantages  of  all,  as  the  subject  may  require.  The  ex- 
pressiveness and  directness  of  pictures  and  solid  repre- 
sentations may  be  combined  with  the  brevity  and  gener- 
ality of  symbols,  and  the  simplicity,  comprehensiveness, 
ease  and  exactness  of  phonetic  writing.  We  are  thus 
furnished  with  the  means  of  retaining  all  our  thoughts 
with  force,  precision,  perspicuity  and  accuracy,  transmit- 
ting them  to  the  most  distant  parts  of  the  world  or  re- 
motest posterity,  and  studying  the  very  words  of  others 
as  deliberately  and  frequently  as  we  please. 

§  2.  OP  THE  RETENTION  OF  KNOWLEDGE  BY  WRITING. — Requisites 
to  render  what  is  written  available. — Things  to  be  attended  to,  in 
writing  for  our  own  use. — How  to  be  secured. — Abstracts. — Copy- 
ing. — Various  Courses.  —  Extracts.  —  Tables.  —  Caution.  —  Defi- 
nitions. 

When  we  have  properly  written  down  anything  which 
we  wish  to  remember,  all  that  is  requisite,  in  order  to  its 
being  available  afterwards,  is,  that  the  writing  should  be 
preserved,  and  that  we  should  remember  where  to  find 
it,  and  what  is  denoted  by  the  characters  and  words  em- 
ployed. This  we  can  generally  do  by  means  of  the 
methods  discussed  in  the  preceding  chapter. 

In  writing  solely  with  a  view  to  the  retention  of  knowl- 
edge, all  that  we  require  to  do,  is,  to  express  ourselves 
with  perfect  clearness  and  precision.  But  this  is  not  so 
easily  effected  as  we  might  suppose.  While  we  distinct- 
ly remember  what  we  have  written,  we  may  think  that 
all  our  expressions  are  quite  unobjectionable;  but  they 
may  present  a  different  aspect  by  the  time  we  have  for- 
gotten what  we  wrote. 

In  order  to  determine  whether  our  expressions  are 
sufficiently  perspicuous  and  exact,  we  should  view  them 


428      RETENTION  BY  EXTERNAL  SIGNS.  [CHAP.  XXIX. 

like  one  who  knows  nothing  of  the  subject,  except  what 
he  derives  from  the  writing;  and  a  little  practice  will 
enable  us  to  do  so  with  little  difficulty.  We  shall  sel- 
dom err  if  we  write  as  we  should  do,  in  addressing  a  per- 
son to  whom  we  desired  to  communicate  clearly  every- 
thing which  is  to  be  remembered,  in  such  a  manner  that 
there  would  be  no  danger  of  his  mistaking  or  hesitating, 
regarding  our  meaning. 

When  all  that  we  require  to  remember  has  been  prop- 
erly written  already,  it  will  be  unnecessary  to  copy  it, 
except  where  we  have  not  easy  and  constant  access  to 
the  works  in  which  it  is  found.  But  it  is  frequently  ad- 
visable to  make  an  abstract  of  a  treatise,  as  this  will  fix 
the  attention  more  closely  than  mere  reading,  and  lead 
to  our  obtaining  a  clearer  view 'of  the  subject.  Mere 
copying  is  generally  of  little  value,  as  the  process  is  so 
purely  mechanical  that  we  may  be  thinking  more  intent- 
ly of  something  else  during  the  operation. 

Facts  which  ought  to  be  remembered,  and  yet  are  not 
contained  in  any  composition  within  constant  and  easy 
reach,  may  be  minuted  in  a  common-place  book.  We 
may  either  have  several  books  of  this  kind,  for  various 
subjects,  or  write  our  entries  continuously  in  one,  and, 
when  it  is  full,  take  another  volume.  Wherever  our 
minutes  are  voluminous  on  each  of  several  subjects,  it  is 
better  to  adopt  the  former  plan,  as  the  different  subjects 
will  thus  be  kept  distinct. 

Where  we  desire  to  note  something  in  a  composition 
to  which  we  have  constant  access,  it  will  generally  be 
sufficient  to  mark  the  passage,  and  give  a  reference  to 
the  book  and  page  in  a  general  index.  But  if  the  mat- 
ter worth  remembering  is  blended  with  much  that  is  not, 
a  minute  in  the  common-place  book  may  save  much  time 
when  vie  afterwards  come  to  refer  to  it. 

In  carrying  out  such  plans,  young  learners  are  apt  to 
collect  a  good  deal  of  dross,  along  with  valuable  matter. 
But  experience  generally  corrects  this  error,  after  a  few 
years :  and  those  who  follow  no  such  plan,  will  often  find 
that  they  formerly  read  much  which  they  would  like  to 
retain  permanently,  but  which  has  now  either  gone  be- 
yond their  reach,  or  lies  they  know  not  where. 

In  minuting  matters  which  abound  with  details,  much 
benefit  may  often  be  derived  from  forming  synoptical 
tables,  which  may  enable  us  to  take  a  bird's  eye  view  of 


SEC.I.]  .WKITING.  429 

the  principal  facts,  and  thus  greatly  assist  remembrance, 
while  they  facilitate  reference.  Running  the  eye  repeat- 
edly and  attentively  over  their  contents,  and  then  review- 
ing them,  will  generally  fix  them  in  the  Memory  better 
than  all  the  machinery  of  Mnemotechny ;  and  the  remem- 
brance of  what  is  thus  acquired  will  greatly  aid  us  in  rec- 
ollecting the  substance  of  the  whole  subject.  Such  aids, 
however,  should  be  used  only  as  auxiliaries,  and  by  no 
means  to  the  exclusion  of  regular  narratives  or  exposi- 
tions :  for  they  necessarily  present  nothing  but  a  skele- 
ton of  leading  facts  or  events,  and  exclude  the  most  in- 
teresting parts  of  the  subject. 

Wherever  we  have  occasion  to  use  a  word  regarding 
whose  exact  meaning  we  may  possibly  experience  some 
difficulty  afterwards,  we  should  either  properly  define  it, 
or  refer  to  some  accessible  definition  which  we  follow. 
Definitions  are  required  only  where  a  term  is  unknown, 
obscure,  equivocal,  or  liable  to  be  forgotten,  as  otherwise 
it  can  cause  us  no  difficulty. 


CHAPTER  XXX. 

OP  THE   MEANS    OF   POSSESSING   A   READY   COMMAND   OP 
OUK   KNOWLEDGE. 

§  1 .  REQUISITES  FOR  POSSESSING  A  READY  COMMAND  OF  OUR  KNOWL- 
EDGE.— Importance  of  this  Subject. — Eight  Requisites,  with  lie- 
marks. 

THE  methods  already  discussed  will  generally  secure 
knowledge  so  that  it  is  not  lost  beyond  the  power  of  rec- 
ollection or  recall.  Many  things  which  never  occurred 
to  us  for  years,  and  which  appeared  to  be  completely 
forgotten,  are  often  vividly  recalled  afterwards,  by  means 
of  some  relation  or  external  object.  But  this  degree  of 
retention  is  quite  insufficient  for  many  purposes.  For  if 
we  form  our  decisions,  and  act,  upon  partial  views  of  a 
subject,  while  we  overlook  or  forget  important  facts,  the 
subsequent  recollection  of  these  will  generally  be  too 
late.  Knowledge  forgotten  or  overlooked  when  it  is 
wanted,  is  of  little  avail.  The  evils  arising  from  this 
source  are  of  frequent  occurrence,  and,  in  many  cases, 
extremely  serious.  In  order  to  avoid  these,  and  to  have 


430  COMMAND  OF  KNOWLEDGE.  [CHAP.  XXX. 

our  knowledge  sufficiently  at  our  command  whenever  it 
is  needed,  the  following  things  are  requisite. 

1.  The  things  to  be  remembered  must  have  been  at- 
tentively considered   and  well  understood,  when  they 
were  originally  learned,  or  at  least  at  some  former  time : 
for  we  do  not  well  remember  what  we  never  rightly 
considered  or  understood. 

2.  They  must  have  been  repeatedly  reviewed  with  at- 
tention, and  their  relations  carefully  observed,  so  that 
they  are  strongly  connected  with  things  which  we  are 
not  in  danger  of  overlooking  or  forgetting. 

3.  Our  knowledge  must  be  classified  and  arranged  ac- 
cording to  its  natural  connections :  otherwise  the  pre- 
ceding requisite  cannot  be  secured  ;  for  if  all  our  knowl- 
edge lies  in  a  confused  mass,  it  is  impossible  to  discover 
the  principal  relations,  and  we  must  rely  chiefly  on  cas- 
ual associations,  which  rather  lead  us  astray  than  guide 
us  to  what  we  ought  to  remember. 

4.  We  must  be  systematic  in  our  habits :  for  if  we  are 
accustomed  to  run  from  one  subject  to  another,  entirely 
unconnected  with  it,  then  back  to  the  .first,  and  so  on,  our 
knowledge  of  them  will  be  so  confused  that  the  same 
evils  will  result  which  are  mentioned  in  the  preceding 
paragraph. 

5.  We  must  cultivate  equanimity,  and  suppress  anx- 
ious and  violent  emotions.     These  are  almost  as  injuri- 
ous in  their  influence  on  memory  as  they  are  in  the  orig- 
inal acquisition  of  knowledge :  for  they  concentrate  the 
attention  on  other  objects  than  those  with  which  it  should 
be  occupied ;  and  hence  we  cannot  call  up  our  knowledge 
when  required,  whereas,  if  our  minds  were  calm  and  un- 
ruffled, the  requisite  cognitions  would  readily  arise. 

6.  We  should  not  attempt  to  recall  our  knowledge 
while  we  are  under  the  influence  of  strong  sensations, 
whether  pleasant  or  painful,  for  the  same  reasons  as  those 
just  mentioned. 

7.  Attention  must  be  paid  to  bodily  health.     Disease 
not  only  distracts  the  attention,  by  the  painful  sensations 
which  accompany  it,  but  it  directly  affects  the  Memory 
by  its  influence  on  the  nervous  system.     Hence  the  ad- 
vantage of  a  close  adherence  to  the  laws  of  health. 

8.  Where  our  knowledge  is  partly  in  writing,  we  must 
have  some  accurate  notion  of  the  nature  of  what  is  writ- 
ten, and  where  it  is  to  be  found :  otherwise  we  cannot 
avail  ourselves  of  it  when  required. 


SEC.  2.]  MEANS  OF  ACQUIRING  IT.  431 

§  2.  MEANS  OF  ACQUIRING  AND  EMPLOYING  THE  PRECEDING  REQUI- 
SITES.— Systematic  Habits. — When  a  Change  of  Plan  is  desirable. 
— Common  Error  of  Young  Persons. — Evils  of  Hurry. — Difference 
between  Reading  and  Study. — Means  of  securing  Equanimity,  and 
moderating  Passion. — Proper  mode  of  dealing  with  Sensations. — 
Power  of  bad  Habits. — Means  of  securing  Health. — Common  Er- 
ror regarding  Writing. — Means  of  rendering  Writing- available. — 
Indexes. — Influence  of  the  Judgement  on  Memory. 

The  modes  in  which  the  three  first  requisites  mention- 
ed in  the  preceding  section  are  to  be  acquired,  have  suf- 
ficiently appeared ;  and  therefore  any  further  considera- 
tion of  them  is  unnecessary. 

In  order  to  secure  systematic  habits,  we  must  form 
some  plan  of  proceeding,  and  adhere  to  it,  as  closely  as 
circumstances  will  permit.  Young  persons  are  apt  to 
abandon  all  system,  as  soon  as  they  find  that  the  one 
planned  cannot  be  carried  out,  owing  possibly  to  its  be- 
ing too  rigid,  and  too  minute  in  its  details.  Yet  if  we 
modify  and  simplify  our  original  scheme,  as  experience 
shows  to  be  desirable,  we  shall  find  that  occasional  inter- 
ruptions and  deviations  will  have  little  influence  on  the 
benefits  derivable  from  systematic  habits.  If  we  find 
that  we  are  frequently  interrupted,  during  the  time  allot- 
ted to  a  particular  pursuit,  we  may  possibly  alter  the 
time  to  advantage.  The  circumstances  of  individuals 
differ  so  much  that  every  one  should  form  his  plans  to 
suit  himself. 

Young  persons  are  apt  to  err  in  expecting  to  accom- 
plish too  much  within  a  given  time :  and  they  often  allot 
a  few  months  to  what  will  require  as  many  years  to  ef- 
fect properly.  To  have  important  results  well  accom- 
plished, generally  requires  time :  and  to  hurry  through 
our  studies  and  investigations,  is  a  very  bad  course,  be- 
cause we  thus  generally  learn  little  and  that  superficially, 
while  even  that  is  apt  to  be  mingled  with  much  error, 
and  to  be  mostly  forgotten,  within  a  short  time.  It  also 
leads  to  a  habit  of  careless  study  and  investigation,  which 
may  cause  innumerable  errors  and  misconceptions.  Hur- 
ry, and  the  confusion  and  oversights  that  uniformly  at- 
tend it,  are  as  injurious  to  remembrance  as  they  are  to 
right  understanding ;  and  therefore  we  should  avoid  it, 
with  the  utmost  care. 

We  should  also  guard  against  the  common  practice  of 
cramming  our  memories  with  the  mere  statements  of 
others,  without  ascertaining  either  their  exact  import  or 


432  COMMAND  OF  KNOWLEDGE.  [CHAP.  XXX. 

their  character  and  bearings.  As  it  is  not  everything 
which  is  swallowed  that  furnishes  bodily  aliment,  but 
only  food,  which  is  properly  digested  and  assimilated ; 
so  it  is  not  what  we  read  or  hear  that  instructs  the  mind, 
but  only  truth,  rightly  understood  and  permanently  re- 
membered.1' 

In  order  to  preserve  an  even  tenor  of  mind,  and  avoid 
the  extremes  of  stormy  passions,  and  the  apathy  which 
inevitably  succeeds,  we  should  note  the  blinding  effects 
of  the  former  on  the  intellect,  and  how  completely  they 
vitiate  every  investigation  performed  while  we  are  under 
their  influence  or  during  the  succeeding  prostration.  The 
habit  of  taking  wide  and  close  views  of  the  subject,  will 
also  conduce  greatly  to  the  same  result.  By  taking  nar- 
row and  one-sided  views  of  a  subject,  we  are  very  liable 
to  work  ourselves  into  a  passion  about  things  which  are 
easily  seen  to  be  quite  insignificant,  when  considered 
closely  and  from  the  true  point  of  view.  Our  feelings 
may  be  both  deep  and  permanent,  without  ever  rising 
into  gusts  of  passion,  which  can  always  be  subdued  by 
extending  our  view  beyond  their  exciting  objects,  or  by 
observing  these  in  their  true  bearings;  and  habit  will 
make  this  course  comparatively  easy. 

As  to  sensations,  it  is  generally  easy  to  abstain  from 
important  investigations  or  decisions  while  we  are  aftect- 
ed  by  any  which  materially  interferes  with  attention. 
Every  one  will  see  the  impropriety*  of  raking  the  Mem- 
ory, and  deciding  important  questions,  while  he  suffers 
acute  pain,  and  the  same  objection  exists  in  the  case  of 
all  violent  feelings,  whether  pleasant  or  painful.  Many 
sensations  are  much  influenced  by  our  habits ;  and  those 
formerly  recommended  will  place  the  most  dangerous  of 
this  class,  such  as  the  appetites,  sufficiently  under  the 
control  of  the  Judgement. 

To  secure  health,  we  must  know  what  its  conditions 
are,  and  rigidly  observe  them :  for  if  we  once  fall  into 
the  habit  of  neglecting  them,  we  are  apt  to  go  on  from 
bad  to  worse,  one  violation  leading  to  a  deeper,  and  the 
strengthening  habits  rendering  a  return  to  better  courses 
more  and  more  difficult.  People  often  flatter  themselves 
that  they  can  easily  abandon  a  habit  when,  in  fact,  they 
do  not  possess  sufficient  resolution  and  energy  to  do  so. 
As  a  man  who  floats  with  the  stream  knows  not  the  dif- 
ficulty of  stemming  the  current,  so  the  slave  of  bad  habits 
knows  not  their  strength  till  he  has  wholly  subdued  them. 


SEC.  2.]  HEALTH — WRITING,  &z.  433 

In  ascertaining  what  are  the  laws  of  health,  we  must 
be"  guided  by  the  disclosures  of  science  regarding  the 
structure  and  wants  of  our  bodily  organization,  and  the 
influence  exerted  on  it  by  the  various  agents  within  and 
around  it.  To  follow  the  opinions  and  practices  of  the 
ignorant,  as  good  guides,  is  like  adopting  the  views  of  a 
cheat  as  a  correct  representation  of  honesty. 

With  respect  to  writing,  we  must  avoid  the  common 
error  of  thinking  that  when  once  we  have  a  thing  writ- 
ten down  in  manuscript,  or  in  a  printed  volume,  it  is 
henceforth  at  our  service,  whenever  it  may  be  required : 
for  it  is  liable  to  be  overlooked  altogether,  or  we  may  be 
unable  to  find  it  in  time,  or  it  may  never  have  been  prop- 
erly understood.  To  obviate  such  difficulties,  we  should 
well  understand  what  we  read  or  write,  and  have  mat- 
ters which  we  require  to  refer  to  afterwards,  entered  in 
an  index.  We  should  also  occasionally  review  our  ac- 
quisitions, so  that  we  shall  have  a  correct  idea  of  their 
nature,  and  neither  search  for  what  is  not  there,  nor  neg- 
lect what  is,  when  there  is  occasion  for  it.  If  we  have 
separate  books  for  different  subjects,  each  should  have 
its  own  index,  in  which  may  be  entered  both  what  we 
have  ourselves  written,  and  what  we  have  read  and  de- 
sire to  note. 

An  index  should  be  so  constructed  that  it  will  enable 
us  to  find  any  passage  to  which  it  refers,  without  diffi- 
culty. In  order  to  this,  the  initial  word  should  be  that 
which  we  are  most  likely  to  refer  to ;  and,  where  there 
is  room  for  doubt,  there  should  be  several,  referring  to 
the  passage,  so  that  we  cannot  fail  to  find  one  or  other 
of  them,  without  much  trouble.  An  index  can  be  made 
by  ruling  a  blank  book,  and  writing  proper  headings,  or 
it  may  be  purchased  ready  made  from  a  stationer. 

In  forming  a  judgement  on  any  important  subject,  we 
should  carefully  run  over  the  various  parts  of  it,  till  we 
have  ascertained  whether  we  have  distinctly  before  us 
everything  requisite  to  obtain  a  correct  view  of  it :  and, 
if  we  have  any  doubt  on  this  point,  we  should  search  and 
think,  till  it  is  fairly  removed.  Such  exercises  strength- 
en the  Memory,  by  concentrating  the  attention  on  partic- 
ular things  ;  and  thus  they  not  only  bring  up  all  our 
knowledge  on  that  occasion,  but  they  render  it  more 
serviceable  for  future  use. 

T 


434 


TABULAR  VIEW.         [CHAP.  XXXI. 


CHAPTER  XXXI. 

TABULAR    VIEW    OP    THE   MEANS    OF    RETAINING    KNOWL- 
EDGE. 

KNOWLEDGE  is  retained  by  means  of 

1.  Attention. 

2.  Clearness  and  distinctness  of  comprehension. 

3.  Extension  of  generalization. 

4.  Repeated  examinations  and  reviews. 

5.  System  and  arrangement. 

6.  Soundness  of  the  nervous  system. 

7.  Relations  of  thoughts,  which  are 
(1.)  artificial,  and 

(2.)  natural,  including  laws  of 
(a.)  Contiguity  and  succession, 
(b.)  Resemblance, 
(c.)  Emotions,  and 
(c/.)  Contraries. 

1.  Commemorative  signs. 

2.  Likenesses. 

3.  Writing  and  printing,  rendered  available  by 
<j  (1.)  Perspicuity  and  precision  of  expression, 

I  (2.)  Proper  definitions, 
(3.)  Abstracts  and  common-place  books,  and 
(4.)  Tables  and  indexes. 


I.  Simple  Remem- 
brance or  Rec- 
ollection, de- 
pendent on 


II.  External  Signs, 
including 


I 


NOTES. 


NOTE  1,  PAGE  13. 

Some  have  defined  Logic  as  "the  science  of  the  laws  of  thought." 
But  this  definition  is  far  too  wide :  for  it  comprises  a  great  portion 
of  Psychology,  even  if  we  limit  the  word  "  thought"  to  intellectual 
thought,  a  limitation  not  justified  by  the  long  established  usage  of 
the  language. 

NOTE  2,  PAGE  38. 

The  Aristotelians  divide  a  proposition  into  three  parts,  the  subject, 
the  predicate  and  the  copula,  or  a  word  connecting  the  two.  Thus, 
in  the  proposition  "man  is  mortal,"  is  is  the  copula.  I  have  not 
adopted  this  division,  because  it  is  based  on  a  particular  mode  of  ex- 
pression, different  from  what  is  generally  used.  In  ordinary  language, 
no  copula  appears,  except  where  the  substantive  verb  to  be  is  used,  in 
some  of  its  forms. 

NOTE  3,  PAGE  44. 

What  is  loosely  termed  a  "moral  certainty,"  seems  to  be  nothing 
but  such  a  high  degree  of  probability  as  will  induce  belief,  in  ordinary 
circumstances.  The  phrase  is  objectionable,  since  it  leads  us  to  con- 
found certainty  with  a  high  degree  of  probability,  things  which  are 
essentially  different.  The  former  does  not  admit  of  degrees ;  the  lat- 
ter does :  the  former  is  wholly  unaffected  by  future  discoveries ;  the 
latter  may  be  reversed  or  destroyed  by  them. 

NOTE  4,  PAGE  50. 

Reasoning  has  been  frequently  defined  as  a  comparison  of  one  thing 
with  another,  and  observing  whether  they  agree  or  disagree.  But 
this  definition  is  very  faulty :  for  it  misrepresents  the  nature  of  rea- 
soning, and  does  not  express  its  peculiar  characteristic.  There  is  in 
reasoning  a  comparison  of  one  thing  with  another ;  but  this  is  done  in 
order  to  ascertain  whether  the  one  necessarily  implies  the  other,  while 
such  comparisons  as  those  expressed  in  the  definition  are  made  for  a 
different  purpose,  and  form  no  part  of  reasoning.  Thus,  if  I  look  at 
two  crows,  perched  side  by  side,  and  see  that  both  are  of  the  same 
color,  here  is  a  comparison  of  one  thing  with  another,  and  a  discern- 
ment of  agreement,  but  no  reasoning  whatever,  since  there  is  no  dis- 
cernment of  necessary  implication  or  connection.  So,  if  I  see  a  crow 
on  a  snow-drift,  and  observe  that  the  former  is  black  and  the  latter 
white,  there  is  a  comparison  of  two  things,  and  a  discernment  of  dis- 
agreement, but  no  reasoning.  In  both  cases,  there  is  simply  an  ap- 
prehension of  two  things,  observed,  by  means  of  abstraction,  to  be 
either  like  or  unlike.  On  the  other  hand,  when  I  see  the  crow  before 


436  NOTES. 

me,  I  know  intuitively,  and  without  any  discernment  of  agreement  or 
disagreement,  that  he  is  nowhere  else  at  that  instant.  Reasoning  is 
an  application  of  Intuition ;  and,  therefore,  where  the  latter  is  not 
employed,  the  former  cannot  exist. 

NOTE  5,  PAGE  51. 

The  Aristotelians  represent  reasoning  as  a  comparison  of  two  pre- 
mises, in  order  to  evolve  the  inference,  whereas  it  consists  of  compar- 
ing the  premise  with  the  inference,  in  order  to  ascertain  whefher  the 
latter  is  necessarily  implied  in  the  former.  Their  view  of  it  is  sub- 
stantially the  same  as  that  mentioned  in  the  preceding  note.  Hence 
they  represent  a  syllogism  as  consisting  of  four,  instead  of  three,  dif- 
ferent parts,  two  premises,  a  connective,  and  an  inference,  which  they 
term  the  conclusion.  They  maintain  that  it  embraces  three  separate 
objects,  or  notions,  two  of  which  are  successively  compared  with  the 
third,  in  the  two  premises,  and  then  pronounced,  in  the  conclusion,  to 
agree  or  disagree  with  each  other. 

The  subject  of  the  conclusion  is  called  the  minor,  and  its  predicate, 
the  major  term :  the  premise  in  which  the  latter  occurs  is  called  the 
major,  and  the  other,  the  minor  premise.     The  subject  of  the  major 
premise,  which  foi-ms  the  predicate  of  the  minor,  is  denominated  the 
middle  term.     Let  us  take  the  following  syllogism  for  an  example : 
Every  man  is  mortal ;  (major  premise) 
John  is  a  man  :  (minor  premise) 

Therefore  John  is  mortal,    (conclusion) 

Here  man  is  the  middle,  mortal,  the  major,  and  John,  the  minor 
term. 

This  view  misrepresents  the  real  process  of  reasoning  in  such  cases, 
which  may  be  variously  expressed  as  follows : 

(1)  John  is  one  of  a  class  individually  mortal ;  (premise) 
But  whatever  belongs  to  a  class  individually,  be- 
longs to  every  one  of  that  class  :  (connective) 
Therefore  John  is  mortal.  (inference) 

(2)  Every  proposition  which  is  true  universally  is  true 

of  every  case  included  in  it :  (connective) 

Now  it  is  true  universally  that  every  man  is  mortal ;  (premise) 
Therefore  the  man  called  John  is  mortal.  (inference) 

The  Aristotelian  syllogism  is  unobjectionable  only  in  those  instances 
where  the  major  premise  is  a  self-evident  truth  which  shows  that  the 
minor  premise  necessarily  implies  the  conclusion,  in  which  cases  it 
evidently  becomes  equivalent  to  what  I  have  termed  the  connective. 
The  two  kinds  of  premise  are  alflte  in  form ;  and  they  never  looked 
any  farther :  yet  they  are  intrinsically  different.  Inductive  proposi- 
tions cannot  form  logical  connectives,  even  when  they  are  universally 
true,  because  they  are  not  self-evident,  and  much  less  where  they  are 
only  generally  true,  as  in  the  instance  just  given. 

Their  vague  and  erroneous  views  of  reasoning  and  syllogism  have 
led  the  Aristotelians  astray  to  such  an  extent  that  a  great  part  of  their 
Logic  is  worthless,  or  even  worse.  "Terms"  seem  to  constitute  the 
corner-stone  of  their  fabric,  and  they  evidently  attended  chiefly  to 
expressions,  without  sufficiently  analysing  the  processes  of  thought. 
Like  their  master,  they  often  lost  themselves  in  words,  and  discussed 
merely  different  forms  of  expression,  while  they  professed  to  unfold 


NOTES.  437 

what  these  denote.  The  whole  machinery  of  their  "moods,"  "fig- 
ures," and  "  rules  for  reduction,"  are  useless  as  an  intellectual  exer- 
cise, and  positively  detrimental  in  the  actual  pursuit  of  truth,  since 
they  only  cloud  and  clog  the  investigator. 

NOTE  6,  PAGE  54. 

Some  affect  to  doubt  whether  extension  is  infinite  ;  but  if  they  seri- 
ously attempted  to  determine  its  boundaries,  they  would  probably  think 
otherwise.  Boundaries  to  extension  are  evidently  as  impossible  as  a 
termination  to  duration.  If  we  think  of  any  part  of  extension,  we 
know  there  is  space  all  round  it ;  and  if  we  think  of  any  part  of  dura- 
tion, we  know  that  part  preceded  and  part  succeeds.  Hence  the 
former  is  infinite,  and  the  latter  eternal. 

Another  absurd  dogma  is,  that  duration  and  extension  are  only 
conceptions  of  the  mind,  and  have  no  existence  beyond  it.  There  is 
nothing  more  self-evident  than  that  these  two  things  necessarily  exist, 
and  that  they  arc  immutable,  and  independent  of  every  other  thing. 
The  dogma  probably  arose  from  confounding  their  nature  with  the 
faculty  by  which  we  discern  ir,  as  if  one  should  maintain  that  the  qual- 
ity of  hardness  exists  only  in  the  points  of  our  fingers,  because  it  is 
through  these  chiefly  that  we  learn  its  nature.  Instead  of  duration 
and  extension  existing  only  in  the  mind,  the  latter  and  every  other 
real  being  exist  only  in  duration  and  extension. 

NOTE  7,  PAGE  Gl. 

The  essential  nature  of  change,  cause,  and  power  are  known  intu- 
itively ;  and,  therefore,  the  terms  expressing  them  neither  require  nor 
admit  of  any  real  definition,  any  more  than  such  words  as  blue,  sweety 
sour,  pleasure,  pain,  &c.,  but  their  precise  signification  is  learned  by 
simply  considering  what  they  arc. 

NOTE  8,  PAGE  61. 

It  has  been  said  that  the  llth  principle  is  not  even  true,  and  much 
less  self-evident,  for  that  the  Sun  attracts  the  Earth  without  any  me- 
dium. This  objection  is  like  declaring  that  a  man  may  be  in  two 
places  at  the  same  instant,  for  that  we  often  see  ourselves  on  the  north 
side  of  a  room  when  we  are  actually  on  the  south  side,  or  that  the 
three  angles  of  a  triangle  are  not  exactly  equal  to  two  right  angles ; 
for  that,  if  we  actually  measure  them,  we  shall  always  find  them  either 
a  little  greater  or  a  little  less.  That  the  Sun  really  attracts  or  draws 
the  Earth,  or  any  other  planet,  is  an  absolute  impossibility,  because  it 
has  no  hold  on  them,  and  consequently  it  can  no  more  draw  them 
than  it  can  draw  empty  space.  As  action  is  only  a  kind  of  motion, 
the  principle  is  only  another  form  of  saying  that  a  being  cannot  be  in 
motion  where  it  is  not,  which  is  as  evident  as  that  a  man  cannot  be 
where  he  is  not. 

NOTE  9,  PAGE  71. 

The  Aristotelians  seem  to  canfQ\m&  judgements,  or  conclusions  from 
premises,  which  have  been  investigated  and  are  believed  to.be  true, 
with  propositions,  without  adverting  to  the  fact  that  the  latter  may  be 
wholly  mental.  Some  of  them  seem  to  have  been  aware  that  we 


438  NOTES. 

reason  in  forming  judgements,  yet  to  have  erred  in  supposing  that 
this  is  different  from  ordinary  reasoning,  and  also  in  thinking  that  we 
reason  whenever  we  discern  the  truth  of  a  proposition,  which  is  by  no 
means  the  case.  All  discernments  are  known  directly,  without  any 
reasoning  whatever. 

Kant's  analytic  judgements  are  simply  truisms,  while  his  synthetic 
judgements  embrace  both  intuitions  and  other  propositions,  so  that  his 
division  only  increases  confusion.  In  order  to  determine  the  logical 
character  of  a  proposition,  we  must  evidently  analyse  it,  so  as  to  un- 
derstand what  it  is  ;  and  then,  in  order  to  determine  whether  it  is  an 
intuition  or  not,  we  must  compare  the  subject  with  the  predicate. 
Consequently  his  analytic  judgements  are  equally  synthetic,  and  con- 
versely, while  neither  class  can  properly  be  termed  judgements  at  all. 
The  truth  of  truisms  is  discerned  precisely  like  that  of  other  intuitions, 
and  the  distinctions  drawn  by  Kant  are  nugatory.  Thus  we  know 
that  "a  man  cannot  be  in  two  different  places  at  the  same  instant," 
just  as  one  knows  that  "every  Englishman  is  a  man." 

NOTE  10,  PAGE  72. 

One  of  the  most  remarkable  cases  of  spectral  illusions  of  which  I 
have  ever  learned,  is  that  related  by  Dr.  R.  Patterson  in  the  Edinburgh 
Medical  and  SurgicalJournal,  for  January,  1843.  In  that  instance,  a 
man  saw  the  figure  of  a  deceased  friend,  heard  him  speak,  and  also 
felt  him  pinch  his  arm.  The  specter  was  so  distinct  that  he  could 
perceive  the  color  of  the  clothes :  yet  he  adds  that  it  was  dim  and  im- 
perfect throughout,  and  that  it  conild  not  for  a  moment  be  considered 
a  real  object.  The  illusion  regarding  his  arm,  he  attributed  to  cramp 
of  the  triceps  muscle. 

NOTE  11,  PAGE  77. 

If  any  person  should  think  that  he  is  immediately  conscious  of  pro- 
ducing the  changes  consequent  on  his  volitions,  I  answer  that  a  care- 
ful consideration  will  show  we  are  conscious  of  nothing  but  the  voli- 
tion and  simultaneous  comprehensions.  We  are  no  more  conscious 
of  moving  our  arms  than  we  are  of  inhaling  the  air  which  is  forced 
into  the  lungs  by  the  pressure  of  the  atmosphere,  when  we  expand 
the  chest. 

NOTE  12,  PAGE  98. 

Direct  likenesses  appear  to  have  been  the  first  signs  employed  for 
perpetuating  knowledge,  as  they  are  more  obvious  and  expressive  than 
any  other ;  and  some  races,  like  the  Aboriginal  Americans,  never  ad- 
vanced beyond  this  method.  It  was  probably  followed  by  symbolic 
writing,  as  being  the  next  link  in  the  series.  This  method  has  been 
most  extensively  used  by  the  Chinese,  who  never  went  beyond  it. 

Phonetic  writing  was  probably  invented  later  than  the  symbolic, 
because,  although  the  simplest  and  most  complete,  it  is  the  least  ob- 
vious and  most  recondite ;  yet  it  is  so  ancient  that  its  origin  and  early 
history  are,  in  a  great  measure,  lost  in  the  mists  of  antiquity.  So  far 
as  we  can  learn,  however,  the  invention  appears  to  be  due  "to  the  an- 
cient Egyptians,  who  certainly  practised  it  at  a  very  remote  period. 
Theory  would  lead  us  to  assume  that  the  earliest  writing  of  this  kind 
was  syllabic,  like  the  Cherokee  alphabet  of  George  Guess,  and  that  of 


NOTES.  439 

the  Veh  people  in  Africa.  But  of  this  there  is  no  clear  proof;  and 
we  find  characters  representing  letters,  and  not  syllables,  in  the  earliest 
extant  specimens  of  phonetic  writing. 

From  Egypt  letters  passed  to  the  Hebrews,  Phoenicians,  Assyrians, 
Babylonians,  and  Indians.  The  Phoenicians  introduced  them  into 
Greece,  whence  they  spread  over  Europe;  and  thence  they  passed 
into  America. 

The  first  letters  were  complete  pictures  of  visible  objects,  the  power 
of  the  letter  being  the  initial  sound  or  articulation  of  the  object's 
name.  Thus,  an  ant,  an  apple,  or  an  axe  might  stand  for  A ;  a  book, 
a  bee,  or  a  box,  for  B,  and  so  on.  Such  are  the  letters  found  on  the 
Egyptian  monuments,  the  hieroglyphics  being  chiefly  inscriptions  in 
such  letters,  often  blended  with  symbolic  and  pictorial  figures.  Even 
in  several  of  the  Roman  characters,  the  original  forms  of  the  objects 
are  still  apparent.  Thus,  A  was  an  ox's  head,  and  D,  a  door,  two  of 
the  angles  having  been  rounded  off  for  convenience  of  writing ;  O 
was  an  eye,  T,  a  cross,  and  U,  a  hook.  The  Hebrew  names  of  the 
letters  still  indicate  the  original  objects ;  for  those  of  the  letters  just 
mentioned  signify  ox,  door,  eye,  cross,  and  hook. 

The  primitive  literal  system  was  afterwards  improved  by  simplify- 
ing the  forms  of  the  letters,  and  employing  only  one  form  to  denote 
one  power,  whereas  originally  several  objects  were  employed,  whose 
names  began  with  the  letter.  The  Greeks  perfected  the  art  of  writ- 
ing, by  expressing  all  the  vowel  sounds,  which  does  not  appear  to  have 
been  previously  done  by  any  nation.  It  was  not  till  upwards  of  fif- 
teen hundred  years  afterwards,  that  the  Syro-Arabian  races  attempted 
to  supply  this  defect,  by  the  clumsy  invention  of  the  vowel  points, 
after  the  old  pronunciation  had  been  lost,  while  the  ancient  Hindoos 
did  not  even  make  the  attempt. 

NOTE  13,  PAGE  107. 

An  analysis  of  the  inductive  processes  shows  the  futility  of  the  dis- 
tinction that  some  have  drawn  between  what  they  term  deductive  rea- 
soning, syllogism  or  ratiocination  and  inductive  reasoning  or  induction. 

We  may  also  see  the  absurdity  of  maintaining  that  a  new  kind  of 
Logic  was  invented  in  the  seventeenth  century,  which  they  distinguish 
as  the  Inductive  Logic,  accompanied  with  a  new  method  of  investiga- 
tion. Induction  indicates  only  the  quantitative  relation  of  the  pre- 
mises to  the  conclusion,  not  the  nature  of  the  reasoning  by  which  this 
is  established ;  and  every  kind  of  inductive  process  was  practiced  in  an- 
cient times.  The  more  rapid  progress  of  knowledge,  in  modern  times, 
has  been  owing,  not  to  any  new  method  of  investigation,  but  to  sev- 
eral other  causes,  some  of  which  are  quite  obvious. 

Another  similar  error  is,  dividing  all  reasoning  into  deductive  and 
inductive.  The  former  term  is  applied  to  those  syllogisms  where  we 
infer  that  a  particular  case  of  a  general  proposition  is  true,  provided 
the  latter  is  true ;  and,  consequently,  when  valid,  it  is  confined  to  nec- 
essary trnth.  By  inductive  reasoning  they  understand  syllogisms  in 
which  it  is  inferred  that  a  general  proposition  is  true,  provided  every 
particular  proposition  embraced  in  it  is  true,  or  has  been  previously 
found  to  be  so,  which  is  evidently  nothing  but  empirical  generaliza- 
tion, and  which  does  not,  in  fact,  include  any  real  process  of  induc- 
tion. Moreover  most  of  our  reasonings  arc  quite  different  from  either 


440  NOTES. 

of  these  processes,  since  both  the  premises  and  inferences  are  particu- 
lar. This  is  usually  the  case  in  the  ordinary  affairs  of  life,  and  very 
frequently  in  scientific  and  historical  investigations. 

NOTE  14,  PAGE  128. 

Some  authors  have  attempted  to  go  beyond  Consciousness,  and  prove 
its  faithfulness :  but  they  are  obliged  to  take  this  for  granted  while 
they  attempt  to  prove  it ;  and,  therefore,  they  reason  in  a  circle.  Thus, 
Kant  attempted  to  prove  the  possibility  of  intuitions ;  but  he  was  obliged 
to  assume  at  the  outset,  not  only  their  possible,  but  their  actual  truth, 
so  that  his  proceeding  was  as  illogical  as  it  was  preposterous. 

So  when  Fichte  says  that  the  Me  puts  forth  a  spontaneous  effort, 
and,  meeting  an  impediment  in  something  external  to  itself,  Con- 
sciousness results,  he  overlooks  the  fact  that  we  can  know  nothing  of 
a  spontaneous  effort  of  the  Me  without  Consciousness,  and  that  such 
an  effort  without  Consciousness  is  a  self-evident  impossibility.  Again, 
when  he  says  "A  is  equal  to  A,"  I  ask  how  does  he  know  this  ?  The 
only  rational  answer  is,  that  it  is  self-evident,  and  requires  no  proof. 
I  reply,  it  is  self-evident  that  every  other  proposition  which  has  the 
same  amount  and  kind  of  evidence  is  equally  certain,  and  equally 
unsusceptible  of  any  proof  which  can  add  to  its  certainty ;  and  of  this 
class  is  every  proposition  expressing  an  intuition  or  any  present  com- 
prehension. 

Similar  remarks  apply  to  Hegel's  process,  when  he  begins  with  pure 
nothing,  and  tells  us  that  something  added  to  nothing,  makes  some- 
thing, which  is  only  a  particular  case  of  the  general  intuition  that  a 
thing  is  what  it  is. 

The  doctrine  of  the  Pyrrhonists  or  universal  sceptics,  labors  under 
the  same  difficulty,  and  is  liable  to  the  same  objection.  Every  think- 
ing being  necessarily  believes  some  proposition  as  certain,  if  it  be  only 
the  reality  of  his  present  thought :  and,  therefore,  the  Pyrrhonist,  in 
expressing  himself  sceptical  concerning  his  doubts,  only  flies  from  one 
certainty  to  plunge  into  another,  which  is  not.  a  whit  more  certain 
than  any  other  discernment. 

NOTE  15,  PAGE  170. 

The  law  of  gravitation  is  often  expressed  by  saying  that  "matter 
attracts  matter,  directly  as  the  mass,  and  inversely  as  the  square  of 
the  distance :"  but  it  would  be  much  more  correct  to  say  that  "pon- 
derable bodies  are  urged  towards  each  other,  by  a  force  which  varies 
directly  as  their  mass,  and  inversely  as  the  square  of  their  distance," 
or,  that  "every  tangible  substance  tends  to  move  towards  every  other, 
with  a  force  which  varies  directly  as  their  mass,  or  quantity  of  solid 
matter,  and  inversely  as  the  square  of  their -distance."  The  proofs 
given  of  this  law  are  quite  fallacious,  so  far  as  they  attempt  to  show 
that  there  is  any  real  attraction,  their  authors  having  overlooked  the 
fact  that  all  the  phenomena  may  result  from  a  compulsive,  instead  of 
an  attractive  force. 

The  heavenly  bodies  have  no  hold  on  each  other ;  and  without  this 
it  is  manifestly  as  impossible  for  them  to  attract  or  draw  each  other, 
as  it  is  to  lift  a  stone  from  the  ground  without  having  anything  at- 
tached to  it  by  which  it  can  be  lifted.  Attraction  without  connection 
is  a  manifest  impossibility.  Another  difficulty,  in  the  way  of  attrac- 


NOTES.  441 

tion,  is,  that  the  bodies  are  inanimate ;  and  therefore  it  is  evidently  as 
impossible  for  them  to  move  either  themselves  or  other  bodies  as  it  is 
for  a  rock  to  move  itself  from  one  mountain  to  another. 

NOTE  16,  PAGE  200. 

The  word  interpretation  was  formerly  employed  in  a  wider  sense,  so 
as  to  include  what  we  now  term  translation:  but  as  the  latter  differs 
essentially  from  what  is  now  generally  understood  by  the  former  term, 
I  have  used  this  in  its  restricted  signification.  The  old  use  of  the 
word  has  evidently  misled  some  logicians,  regarding  the  true  nature 
of  interpretation.  They  say  that  the  interpreter  should  be  thoroughly 
acquainted  with  the  language,  and  familiar  with  the  subject  of  which 
the  writing  to  be  interpreted  treats.  These  remarks  are  applicable  to 
translation ;  but  to  apply  them  to  interpretation  reminds  us  of  the 
old  advice  that  we  should  not  go  into  the  water  till  we  have  learned 
to  swim :  for  it  is  only  by  numerous  exercises  of  interpretation  that  a 
thorough  acquaintance  with  the  language  can  be  acquired ;  and  we 
frequently  study  a  work  which  treats  of  a  subject  regal-ding  which  we 
know  little  or  nothing,  and  which  we  expect  to  learn  from  it. 

NOTE  17,  PAGE  244. 

The  ordinary  names  of  the  various  divisions  of  organic  nature  are 
mostly  Latin ;  and,  even  when  they  are  derived  from  some  other 
source,  they  are  usually  given  in  a  Latin  form.  Attempts  have  been 
made,  by  several  naturalists,  to  substitute  terms  in  their  own  vernacu- 
lar languages :  but  none  of  these  have  yet  been  generally  adopted ; 
and  it  is  to  be  hoped  that  they  never  will.  For  the  Latin  terms  pos- 
sess the  great  advantage  of  being  familiar  to  naturalists  throughout 
the  world,  while  they  are  free  from  the  peculiar  difficult  or  repulsive 
sounds  that  occur  in  others.  It  is  evidently  very  desirable  that  scien- 
tific terms  should  be  common  to  all  mankind,  without  any  change  of 
spelling  or  pronunciation ;  and,  therefore,  where  such  terms  exist,  they 
should  be  retained,  till  they  can  be  superseded  by  better,  of  which  there 
is  no  immediate  prospect. 

The  ordinary  mode  of  naming  genus  and  species  is,  to  take  the  Latin 
name  of  some  well-known  genus  for  the  generic  narn^e,  and  that  of  the 
other  species,  in  the  same  language,  for  the  specific  designation.  Thus, 
bos,  the  generic  name  of  the  ox  tribe,  is  the  Latin  for  the  common 
ox,  and  bubalus  for  the  common  buffalo.  The  species  whence  "the 
generic  name  is  taken,  is  distinguished  by  some  peculiar  Latin  epithet. 
Thus,  the  common  ox  is  bos  taurus,  the  latter  word  being  the  Latin 
for  the  common  bull.  So  the  cat  is  distinguished  by  adding  to  the 
generic  term  felis  (which  is  the  Latin  for  the  common  cat)  the  speci- 
fic term  catus,  a  Latinized  form  of  cat,  a  word  which  is  found  in  sev- 
eral of  the  Aryan  languages.  The  specific  name  for  the  common  cat 
is,  therefore,  fells  catus,  the  lion  being  similarly  denominated  felis  leo, 
the  tiger,  felis  tigris,  the  purna,  cougar  or  American  lion,  felis  conco- 
lor, — the  panther,  felis  pardus,  and  so  forth.  So  the  dog  is  termed 
cards  farniliaris,  canis  being  the  Latin  for  dog:  cam's  lupus  is  the  wolf, 
and  cams  vulpes,  the  fox. 

If  the  species  or  genus  has  no  Latin  name,  naturalists  adopt  the 
native  name,  or  one  which  indicates  a  striking  peculiarity  of  the  di- 
vision, or  the  name  of  its  discoverer,  or  of  some  of  his  friends  or  favor- 

T  2 


442  NOTES. 

ites.  Thus,  bos  arnee  is  the  specific  name  of  the  arnee,  or  Indian  buf- 
falo— bos  grunniens,  that  of  the  yak,  or  grunting  ox  of  Central  Asia — 
and  bos  cajfer,  the  South  African  buffalo.  So  the  gigantic  genus  of 
conifer  recently  discovered  in  California,  is  termed  by  some  Washing- 
tonia,  and  by  others  \Vellingtonia,  while  a  species  of  pins  lately  discov- 
ered in  the  same  country,  is  termed  pinus  Jeffreyi,  from  Jeffrey,  its 
discoverer. 

It  is  to  be  regretted  that,  in  naming  newly  discovered  groups,  the 
principle  has  not  been  universally  followed  of  adopting  a  name  which 
indicates  the  most  remarkable  peculiarity  of  the  division,  since  other 
methods  furnish  no  direct  information  regarding  its  nature. 

NOTE  18,  PAGE  252. 

The  categories  of  Aristotle  consisted  of  a  few  heads,  such  as  time, 
place,  quality,  &c.,  to  one  or  other  of  which  it  was  supposed  every  ques- 
tion might  easily  be  referred ;  and  they  were  apparently  designed  to 
assist  in  finding  and  keeping  in  view  the  point  at  issue  in  an  investiga- 
tion. But  all  such  attempts  are  futile.  For  either  the  heads  will  be 
so  general  as  to  be  good  for  nothing,  or  the  enumeration  will  run  into 
a  mass  of  details  too  burdensome  for  the  memory,  and  possibly  inac- 
curate or  incomplete  after  all. 

A  careful  consideration  of  the  subject  will  always  show  the  nature 
of  the  question  much  better  than  any  categories  :  for  many  questions 
are  of  a  complex  nature,  and  the  inquiry  branches  into  several  heads, 
so  that  the  categories  would  mislead,  rather  than  guide. 

NOTE  19,  PAGE  334. 

I  use  the  singular,  instead  of  the  plural,  form  of  the  names  of  sev- 
eral sciences,  not  merely  because  all  nations  except  those  who  speak 
English,  do  so,  but  because  the  sciences  are  one,  and,  therefore,  the 
singular  is  the  proper  form.  It  is,  in  reality,  as  absurd  to  talk  of  Me- 
chanics, Optics  and  Ethics,  as  to  speak  of  Iconics,  Rhetorics  and  As- 
tronomies, although  our  ears  are  more  familiar  with  the  former  than 
with  the  latter  terms. 

NOTE  20,  PAGE  340. 

Ethnography  differs  so  widely  in  its  nature  and  subjects  from  what 
is  properly  termed  Geography  that  they  ought  to  be  distinguished  by 
different  names.  The  latter  is  purely  scientific,  while  the  former  is 
only  partially  so.  Yet  its  truths  possess  so  much  generality  that  they 
cannot  properly  be  classed  with  History  or  Biography,  which  discusses 
only  particular  facts  and  occurrences. 

NOTE  21,  PAGE  347. 

As  the  general  uses  of  knowledge  have  been  discussed  in  the  Intro- 
duction, those  pointed  out  in  Part  IV.  are  only  the  special  uses  of  the 
various  branches. 

NOTE  22,  PAGE  347. 

Various  methods  have  been  employed  in  establishing  the  funda- 
mental principles  of  the  Higher  Analysis,  or,  as  it  is  often  termed,  the 
Infinitesimal  Calculus.  But  the  method  of  limits,  or  of  prime  and  ul- 


NOTES.  443 

tlmate  ratios,  which  was  first  employed  by  Newton,  is  that  which  is 
now  generally  adopted;  and  it  appears  to  be  the  best,  as  it  leads  to 
the  required  principles  by  the  clearest  and  easiest  steps.  The  princi- 
pal difficulty  attending  it  is,  that  we  cannot  comprehend  the  infinity 
of  changes  or  variations  which  it  assumes ;  and  hence  we  are  apt  to 
conclude  that  they  cannot  be.  But  the  following  simple  theorem  en- 
ables us  to  surmount  the  difficulty. 

A  quantity  ivhich  gradually  diminishes,  so  that  it  becomes  less  than  any 
assignable  quantity,  vanishes,  or  becomes  nothing. 

If  the  quantity  does  not  become  absolutely  nothing,  let  its  least  value 
be  x :  then,  since  it  becomes  less  than  any  assignable  quantity,  it  be- 
comes less  than—:  that  is,  a  quantity  becomes  less  than  the  thou- 
sandth part  of  itself,  which  is  absurd.  Therefore  the  diminishing 
quantity  becomes  nothing. 

It  follows,  as  a  corollary,  from  this  theorem,  that  when  a  quantity 
approaches  indefinitely  near  another,  it  ultimately  coincides  with  it, 
or,  as  it  is  otherwise  expressed,  it  becomes  equal  to  it  at  the  limit. 

Another,  and  more  general,  corollary  is,  that  a  quantity  which  be- 
comes less  than  any  assignable  quantity,  may  be  rejected  in  a  final 
expression,  without  changing  the  value  of  the  expression.  The  former 
corollary  is  only  a  particular  case  of  this  one.  For,  let  C  be  a  con- 
stant quantity,  x  a  variable  which  approaches  indefinitely  near  it,  and 
d  x  the  quantity  by  which  x  differs  from  C:  then 

x+dx=C; 

and,  therefore,  by  the  second  corollary,  when  d  x  becomes  indefinitely 
small,  or  less  than  any  assignable  quantity, 

x=C, 
which  is  the  first  corollary,  analytically  expressed. 

These  theorem  and  corollaries  also  furnish  the  best  foundation  for 
the  doctrines  of  proportion,  as  they  enable  us  to  treat  incommensura- 
bles  like  commensurables. 

NOTE  23,  PAGE  352. 

To  the  inductive  laws  of  motion  usually  given  by  writers  on  Mechan- 
ic, should  be  added  the  following : 

The  momentum  of  a  body  is  proportional  to  its  mass  multiplied  by  its 
velocity.  This  law  is  sometimes  introduced  as  a  definition  :  but  it  is 
evidently  a  theorem ;  and  it  is  established  like  other  inductive  laws 
of  motion. 

The  momentum  of  a  body  means  its  moving  force,  or  its  power  to 
move,  penetrate,  break,  tear,  or  crush,  another  body  with  which  it 
comes  in  contact,  or  which  it  otherwise  affects.  The  mass  of  a  body 
means  its  quantity  of  solid  matter,  which  is  generally  measured  by  its 
weight.  The  velocity  of  a  body  is  either  actual  or  virtual.  The  for- 
mer is  that  with  which  it  actually  moves :  the-  latter  is  that  with  which 
it  would  move,  if  some  counteracting  force  were  withdrawn,  and  is 
that  meant  in  the  proposition. 

NOTE  24,  PAGE  358. 

Attention  has  now  been  so  extensively  directed  to  every  branch  of 
Astronomy  that  there  is  little  probability  of  any  entirely  new  field  be- 
ing discovered ;  yet  the  immense  subject  of  the  fixed  stars  still  offers 


444  NOTES. 

many  problems  for  future  observations,  which  it  will  require  many 
generations  to  solve;  and  even  the  field  of  the  solar  system  is  by  no 
means  exhausted. 

NOTE  25,  PAGE  3G2. 

The  identity  of  the  law  of  intensity  of  light,  heat  and  electricity  with 
that  of  the  force  of  gravitation,  is  an  indication  that  the  phenomena 
of  gravitation  result  from  undulations  of  ether,  passing  incessantly,  at 
very  short  intervals,  through  every  point,  in  all  directions.  The  fact 
that  we  can  clearly  see  any  one  point  in  a  room  from  any  other, 
proves  that  this  is  the  case  with  the  waves  of  light ;  and  it  may,  there- 
fore, hold  true  of  those  of  gravitation. 

If  we  suppose  these  undulations  so  small  that  they  penetrate  through 
all  ponderable  bodies,  and  impinge  against  the  atoms- which  compose 
them,  those  phenomena  will  be  a  necessary  consequence.  A  single 
atom  would  be  apparently  unaffected,  since  the  forces  acting  on  it  in 
'all  directions  would  be  equal:  but  when  there  were  two  atoms,  the 
waves  on  the  outer  sides  would  force  them  together,  because  those 
flowing  in  the  opposite  direction  were  stopped  by  the  intervening  body. 
The  nearer  the  atoms,  the  more  interfering  waves  would  be  stopped ; 
and  the  force  would-follow  the  law  of  the  inverse  square,  for  the  same 
reason  that  a  person  at  two  yards  from  a  fire  receives  only  one  fourth 
as  much  heat  as  when  he  is  one  yard  distant.  As  every  atom  would 
be  similai-ly  affected,  gravity  would  vary  directly  as  the  mass,  or  num- 
ber of  atoms. 

According  to  this  view,  gravitation  is  a  compulsive,  and  not  an  at- 
tractive force,  as  it  is  constantly  termed ;  or,  in  other  words,  it  is  a 
pushing,  and  not  a  pulling  force.  It  would  also  follow  that  gravita- 
ting bodies  do  not  in  any  way  affect  each  other,  except  where  they  ai-e 
in  contact.  But  these  results  can  form  no  real  objection  to  the  doc- 
trine :  for  the  demonstrations  given  of  the  law  of  gravitation  wholly 
fail  to  prove  that  there  is  any  real  attraction,  or  that  the  bodies  really 
affect  each  other.  All  they  prove  is,  that  the  bodies  move  towards 
each  other;  and  this  is  explained  by  the  one  theory  quite  as  well  as 
by  the  other. 

We  may  suppose  that  the  waves  of  light,  heat  and  electricity  origin- 
ate in  the  gravitation  waves  being  disturbed,  and  thus  generating  them, 
owing  to  the  peculiar  form,  position  or  motion  of  the  atoms  of  ponder- 
able bodies,  although  these  positions  and  motions  might  have  been 
produced,  in  the  first  instance,  by  the  gi-avitation  waves  themselves. 

If  we  further  suppose  that  the  gravitation  waves  sometimes  impinge 
against  substances  which  they  cannot  permeate  without  causing  their 
parts  to  adhere  closely  to  each  other,  either  directly  or  by  means  of 
new  waves,  we  should  have  an  explanation  of  cohesion  and  chemical 
affinity. 

The  elasticity  of  bodies  might  be  explained  by  supposing  that  wher- 
ever some  of  the  atoms  were  pulled  a  little  apart  while  others  were 
forced  nearer  than  usual,  new  waves  were  generated  which  exerted  a 
repellent  action  on  the  latter,  and  a  compulsive  force  on  the  former. 

The  peculiar  phenomena  of  heat  and  electricity  are  easily  explain- 
ed on  this  hypothesis.  Thus,  the  melting  and  expanding  power  of 
heat,  and  its  influence  on  chemical  action,  would  result  from  its  strong 
waves  simply  counteracting  the  cohesive  force  of  those  of  gravitation, 
as  in  fluids ;  or  they  might  even  produce  a  repulsive  contrary  force, 


NOTES.  445 

as  in  gases.  In  both  cases  we  might  expect  the  distance  of  the  atoms 
from  each  other  to  be  increased,  which  would  account  for  the  expan- 
sion that  usually  takes  place,  although  the  form  of  these  atoms  might 
be  such  that  they  would  become  more  compactly  arranged,  and  con- 
sequently occupy  less  space,  on  being  heated,  as  in  the  case  of  melted 
iron,  and  water  near  the  freezing  point. 

The  effects  of  heat  and  electricity  on  chemical  action  would  result 
from  their  loosening  the  particles,  and  thus  favoring  a  combination 
of  the  elements,  in  some  cases,  while  the  increased  expansibility  of  a 
gas  would  cause  it  to  fly  off,  in  other  cases,  as  in  the  common  process 
of  burning  limestone,  or  what  is  technically  termed  roasting  metallic 
ores. 

The  attractive  and  repulsive  phenomena  of  electricity  Avould  be 
produced  by  its  waves  interfering  Avith  each  other,  according  to  the 
various  directions  in  which  they  flowed.  So,  latent  heat  would  result 
from  the  waves  being  destroyed  by  resistance  in  one  case,  like  those 
of  light  falling  on  a  black  body,  and  being  again  re-generated  from 
the  rapid  motion  of  the  particles,  in  assuming  their  former  state. 

Thus  the  gravitation  waves,  and  the  peculiar  forms  of  the  various 
ponderable  substances,  may  account  for  a  great  portion  of  the  phe- 
nomena of  the  physical  creation,  as  their  immediate  causes.  But  we 
must  look  to  a  presiding  Intelligence,  not  only  to  form  and  arrange 
those  substances  originally,  but  also  to  sustain  the  motions  of  the 
ethereal  particles,  by  continued  and  most  powerful  acts.  This  is  pos- 
sibly effected  by  undulations  propagated  from  a  center,  as  light  pro- 
ceeds from  the  Sun,  and  reflected  from  the  various  points  of  a  solid 
sphere,  surrounding  the  visible  creation. 

If  it  be  objected  that  this  arrangement  would  render  gravitation  of 
unequal  force,  I  answer  that  we  have  no  proof  it  is  not  so ;  we  do  not 
know,  for  instance,  that  the  force  of  gravitation  is  the  same  at  the 
nearest,  and  much  less  at  the  remotest,  fixed  star,  as  it  is  at  the  Sun ; 
and  the  space  occupied  by  the  solar  system  is  only  a  very  small  part 
of  the  universe.  It  may  be  further  answered  that  the  particles  of 
ether  may  be  so  arranged  as  to  compensate  for  the  unequal  action  of 
the  central  force,  in  different  parts  of  space. 

NOTE  26,  PAGE  364. 

Organic  specimens  have  generally  been  preserved  by  drying  them, 
or  putting  them  in  alcohol ;  but  they  could  be  preserved  in  a  vacuum 
better,  probably,  than  by  any  other  means,  although  this  method  has 
been  little  used,  if  at  all. 

NOTE  27,  PAGE  373. 

The  grand  outlines  of  Geology  have  already  been  clearly  traced : 
but  the  science  is  very  extensive,  and  much  remains  to  be  done,  in 
filling  up  details,  modifying  propositions  which  may  have  been  too 
loosely  or  generally  expressed,  and  settling  doubtful  or  disputed  points. 
Several  of  the  terms,  also,  should  be  superseded  by  others,  of  a  more 
general  and  scientific  character. 

NOTE  28,  PAGE  376. 

Logic  properly  embraces  the  few  truths  relating  to  the  general  prop- 
erties of  beings,  which  have  been  attempted  to  be  formed  into  a  sep- 


440  NOTES. 

arate  science,  under  the  name  of  Ontology.  This  is  variously  defined 
as  the  science  of  "being  in  general,"  and  "that  which  investigates  the 
nature  and  properties  of  being  or  reality,  as  distinguished  from  phe- 
nomena or  appearances."  Our  knowledge  of  such  properties  is  whol- 
ly intuitive,  and  far  too  scanty  to  form  a  science. 

What  some  term  the  science  of  ^Esthetics  is  only  a  part  of  that  di- 
vision of  Psychology  which  treats  of  the  emotions.  Discussions  re- 
garding the  modes  of  producing  aasthetical  emotions  belong  to  art, 
and  not  to  science. 

To  Logic  and  Psychology  belong  most  of  the  subjects  discussed  un- 
der the  vague  names  of  Pneumatology  and  Metaphysics,  and  all  the  rest 
properly  belong  to  other  branches  of  knowledge,  so  that  those  divisions 
should  be  discarded. 

NOTE  29,  PAGE  385. 

The  subjects  discussed  under  the  name  of  Political  Economy  belong 
partly  to  Morality,  partly  to  Jurisprudence,  and  partly  to  Technology. 
The  combination  forms  a  compound  of  incongruous  elements  which 
were  much  better  discussed  under  the  heads  to  which  they  respective- 
ly belong.  What  relates  to  laws,  is  best  discussed  in  Jurisprudence ; 
the  duties  of  an  individual,  in  regard  to  his  vocation,  belong  to  Mo- 
rality ;  and  the  mode  in  which  an  art  or  profession  should  be  carried 
on  or  exercised,  in  order  to  make  it  most  useful  or  profitable,  rightly 
belongs  to  Technology,  and  has  nothing  to  do  with  political  science. 

NOTE  30,  PAGE  390. 

From  misunderstanding  some  passages  in  the  eleventh  chapter  of 
Genesis,  many  have  supposed  that  the  original  language  of  mankind 
was  miraculously  formed  into  several  at  Babel.  But  there  is  no  real 
foundation  in  Scripture  for  any  such  opinion.  The  literal  rendering 
of  the  first  verse  of  the  chapter  referred  to,  is — "And  the  whole  Earth 
was  of  one  lip  and  of  one  words."  The  last  term  certainly  means 
language,  as  it  does  not  admit  of  any  other  interpretation  in  this 
place:  and,  consequently  "lip"  must  mean  something  else:  otherwise 
the  expression  would  be  absurdly  tautologous :  and  it  is  observable  that 
the  expression  "words"  is  not  repeated,  in  any  part  of  the  narrative. 

The  literal  rendering  of  the  last  clause  of  the  seventh  verse  is — 
"that  a  man  will  not  hear  the  lip  of  his  neighbour,"  which  is  Avell 
rendered  in  the  old  Greek  and  Latin  versions — "that  one  will  not 
hear  the  voice  of  his  neighbour."  The  word  rendered  "  hear"  (which 
is  of  very  frequent  occurrence  in  the  Old  Testament),  properly  signi- 
fies hear  in  Hebrew  as  much  as  this  does  in  English.  It  is  sometimes 
employed  figuratively  to  denote  understand :  but  this  is  unusual.  Here 
it  evidently  means  listen  to  or  regard;  and  the  confusion  spoken  of 
was  simply  dissension,  arising  from  differences  of  opinion,  the  instru- 
ment, by  a  common  figure  of  speech,  being  put  for  that  which  is  ex- 
pressed. 

The  more  closely  and  extensively  languages  are  examined,  the  more 
irresistible  appears  the  evidence  of  their  common  origin.  The  old 
philologists  were  often  mistaken  in  their  views  regarding  the  deriva- 
tion of  languages :  for  when  they  found  several  that  closely  resembled 
each  other,  they  inferred  that  all  the  rest  must  have  sprung  from  the 
one  which  they  thought  the  oldest,  a  process  like  inferring  that  the 


NOTES.  447 

oldest-looking  of  several  sisters  must  be  the  mother  of  all  the  rest. 
Yet  the  affinities  on  which  they  argued  were  mostly  real. 

The  theory  which  attributes  the  affinities  of  language  to  the  simi- 
larity of  the  organs  of  speech,  in  the  various  races  of  men,  is  refuted 
by  several  well-known  facts.  Thus,  the  Turks  resemble  the  Germans 
in  physical  structure,  much  more  than  do  the  Hindoos ;  and  yet  the 
languages  of  the  latter  resemble  the  German  much  more  closely  than 
the  Turkish  does.  Again,  words  which  appear  to  be  derived  from 
imitating  natural  sounds,  widely  differ,  in  various  languages,  while 
words  which  have  no  such  origin,  are  alike.  Thus,  the  words  for 
weep  are  entirely  different,  even  in  several  of  the  kindred  Aryan  lan- 
guages, while  the  word  sack  is  found,  with  the  same  signification,  in 
several  distinct  classes  of  languages,  along  the  whole  length  of  the 
old  world. 

If  we  request  several  unconnected  persons  to  imitate  some  natural 
sound,  such  as  the  note  of  a  bird,  they  will  generally  pronounce  it  very 
differently,  Avhile  the  similarities  of  language  are  apparent  in  words 
whose  particular  form  must  have  been  casual,  and  also  in  the  struc- 
ture of  language,  as  well  as  in  the  vocabularies. 

To  compare  human  speech,  with  its  myriads  of  words  and  its  com- 
plexity of  structure,  to  the  few  instinctive  and  inarticulate  cries  of  the 
lower  animals,  could  proceed  only  from  persons  who  never  properly 
examined  the  subject.  To  those  who  have,  the  comparison  will  ap- 
pear absurd,  as  it  really  is. 

It  -is  observable,  however,  that  the  facts  just  mentioned  do  not  war- 
rant Miiller's  theory,  that  language  has  sprung  from  "phonetic  types, 
produced  by  a  power  inherent  in  human  nature."  For  words  have 
been  so  much  changed  that  the  onomatopoetic  origin  of  many  will 
have  disappeared  in  that  way,  while,  in  other  cases,  it  will  have  van- 
ished by  mei-e  epithets  or  learned  terms  having  usurped  the  original 
words.  Of  this,  the  whip-poor-will  furnishes  a  recent  instance.  Al- 
though the  bird  is  generally  known  by  no  other  name  throughout  the 
United  States,  yet  its  scientific  name  is  totally  different,  being  capri- 
muli/us  vociferus. 

That  language  originated  partly  in  onomatopoeia  and  ejaculation, 
admits  of  no  doubt ;  and  when  we  consider  the  power  of  man  to  form 
compounds,  and  the  natural  tendency  to  contraction  and  alteration, 
during  successive  ages,  we  shall  see  that  those  two  sources,  taken  in 
connection  with  man's  ordinary  intellect,  are  amply  sufficient  to  ac- 
count for  all  the  phenomena  of  speech.  The  supposed  "inherent 
power"  is,  therefore,  destitute  of  a  tittle  of  evidence  that  it/  ever  ex- 
isted: that  it  does  not  exist  now,  is  admitted.  The  slightest  appli- 
cation of  the  doctrine  of  permutations  and  combinations,  will  show 
that  onomatopoetic  and  instinctive  ejaculations  would  readily  produce 
many  more  words  than  the  total  number  of  primitives  found  in  any 
language. 

The  more  complex  structure  of  Sanscrit  and  Greek,  compared  with 
English  or  French,  has  been  applied  as  an  argument  in  support  of  the 
original  superiority  and  divine  origin  of  language.  But,  besides  the 
facts  already  stated,  there  are  several  others,  which  show  the  worth- 
lessness  of  this  argument.  Many  of  the  aboriginal  languages  of  Af- 
rica and  America  are  much  more  complex  than  either  Sanscrit  or 
Greek ;  and  yet  they  are  found  ill  adapted  for  conveying  thought  on 
abstract  subjects,  with  either  force  or  precision. 


448  NOTES. 

The  copiousness  of  inflection,  which  has  been  frequently  adduced  as 
a  striking  proof  of  tha  superiority  of  the  ancient  classic  languages, 
originated  chiefly  in  colloquial  blunders,  or  in  confounding  distinc- 
tions which  ought  to  have  been  preserved.  The  personal  inflections 
of  verbs,  for  instance,  arose  from  confounding  the  personal  pronouns 
with  the  verbs  of  which  they  were  nominatives. 

Aj$  a  simple  machine,  which  performs  well  all  the  requisite  func- 
tions, is  superior  to  one  which  contains  many  useless  parts  ;  so  a  lan- 
guage which  contains  no  useless  inflections,  is,  so  far,  superior  to  one 
which  exhibits  many  such  cumbrous  appendages.  Thus,  in  the  in- 
stance just  mentioned,  it  is  better  to  indicate  the  person  by  a  separate 
word,  as  in  English,  than  to  blend  nominative  and  verb,  as  is  done  in 
Latin  and  Greek.  The  natural  consequence  of  the  latter  practice  has 
been,  that  the  meaning  of  the  affix  was  lost ;  and  hence  the  pronoun 
came  to  be  repeated,  or  used  superfluously.  Ego  am-o  is — I  love-I ; 
illi  am-ant  is — they  love-they ;  and  homines  dic-unt  is — men  say-they. 

The  wide  room  for  variety  in  the  collocation  of  words,  allowed  by 
the  classic  languages,  tended  to  produce  confusion  in  the  speaker  or 
writer,  and  impeded  a  right  understanding  of  his  expressions,  on  the 
part  of  his  hearers  or  readers. 

As  every  ancient  language  must  have  undergone  numerous  altera- 
tions from  time  to  time,  long  prior  to  the  invention  of  writing,  it  fol- 
lows that  the  original  language  of  mankind  can  nowhere  be  found. 
Nor  can  we  say,  with  any  degree  of  certainty,  what  language  most  re- 
sembles it.  But  as  it  must  have  been  a  very  rude  and  scanty  speech, 
the  question  is  one  of  little  interest,  and  of  no  practical  importance. 

NOTE  31,  PAGE  394. 

Although  much  has  been  already  accomplished,  yet  the  application 
of  scientific  principles  to  the  improvement  of  the  arts  still  presents  a 
wide  field  for  invention.  For  many  of  those  who  attended  to  this 
subject  either  failed  to  see  the  most  pressing  wants  of  art,  or  mistook 
the  best  modes  of  supplying  them.  Hence  their  inventions  were  either 
unimportant  or  inefficient. 

NOTE  32,  PAGE  403. 

Besides  the  Christian,  the  following  are  the  principal  epochs  used 
in  History: 

1.  The  Creation  of  Man,  3760  years  before  Christ,  according  to  the 
Hebrew  reckoning,  or  5509  according  to  the  Septuagint.     This  epoch 
is  used  by  the  Jews,  and  often  by  Christians,  in  treating  of  events 
prior  to  the  Christian  era. 

2.  The  Olympic  epoch  of  the  Greeks,  776  years  B.C.,  from  which 
they  reckoned  by  olympiads,  or  periods  of  four  years. 

3.  The  Building  of  Rome,  752  years  B.C.     This  epoch  was  long 
used  by  the  Romans. 

4.  The  epoch  of  Budda,  544  B.C.,  used  by  the  Buddists  through- 
out Southern  and  Eastern  Asia. 

5.  The  Samvat,  or  era  of  Vicramaditya,  beginning  56  years  B.C., 
used  by  the  Northern  Hindoos. 

6.  The  Saca,  or  era  of  Sulwanalt,  commencing  A.D.  78,  used  in 
Southern  and  Western  India. 

7.  The  Hejira,  or  flight  of  Mohammed  from  Mecca,  16th  July, 
A.D.  622,  generally  used  by  Mohammedans. 


INDEX. 


A. 

Aberrancies,  definition  of,  250. 
"  illustration  of,  251. 

of  confusion,  306-3 16. 
"          of  appeals  to  authori- 
ty, 316-320. 

Aberrancies,  of  appeals  to  desires, 
320-324. 

Aberrancies,  table  of,  327. 

Abridgements,  how  distinguished, 
233. 

Absolute  proposition,  definition  of, 
39. 

Abstract  quantity,  principles  re- 
garding, 54-58. 

Abstraction,  definition  of,  35. 
"          two  kinds  of,  35. 

Abstracts,  uses  of,  138,  417. 

Accumulating  probabilities,  soph- 
ism of,  299. 

Acoustic,  definition  of,  335. 

"        foundations  and  uses  of, 
354. 

Adopting  a  mean,  paralogism  of, 
280,281. 

^Esthetics,  its  nature,  Note  28,  446. 

^Etiology,  definition  of,  336. 

Affirmative  proposition,  definition 
of,  39. 

Agencies  (see  Causes  and  Determ- 
ining Conditions). 

Algebra,  definition  and  divisions 
of,  333. 

Algebra,  uses  of,  346,  347. 

Alphabets,  origin  of,  Note  12,  438, 

Altering  propositions,  sophism  of, 

288,  289. 
Alternative  proposition,  definition 

of,  39. 

Ambiguity,  latent,  207. 
Ambiguous  expression,  paralogism 

of,  276. 


Ambiguous   expression,  modifica- 
tions of,  276,  277. 

Analogy,  definition  of,  158. 
"       uses  of,  158,  159, 178. 
"       abuse  of,  159. 

Analysis,  Mathematical,  definition 
of,  333. 

Analysis,   Mathematical,    charac- 
teristics of,  345. 

Analysis,  Mathematical,  uses  of, 
346,  347. 

Analysis,  mental,  remarks  on,  160. 

Analytical     Geometry,  definition 
and  divisions  of,  333,  334. 

Analytical  Geometry,  its  relation 
to  Analysis,  345,  346. 

Analytical  Geometry,  uses  of,  350. 

Anatomy,  definition  and  divisions 
of,  336. 

Anatomy,  foundations  and  uses  of, 
365. 

Angles,  principles  regarding,  55. 

Animate  substances,  definition  of, 
58. 

Animate  substances,  principles  re- 
garding, 58-60. 

Antecedent,    how     distinguished 
from  cause,  61. 

Antecedent  and  consequent,  mne- 
monic law  of,  420. 

Antiquated  significations,  when  to 
be  adopted,  202,  203. 

Antiquities,  definition  of,  340. 

Appeals  to  authority,  aberrancics 
of,  316-320. 

Appeals  to  desires,  aberrancies  of, 
320-324. 

Apprehensions,  nature  of,  32. 

"  inferences  from,  33, 

74-85. 

Apprehensions,  reality  of,  45,  46, 
73. 

Apprehensions,  requisite  to,  46. 


450 


INDEX. 


Apprehensions,  how  distinguished.' Attention,  its  importance,  46-48, 


from  ideas,  46,  47,  72,  73. 


Apprehensions,  distinct  from  their  Attention,  how  secured,  253,  254, 


121,  122,214. 


causes,  73,  74. 
Apprehensions,    subsidiaries 
86-91. 


of, 


Apprehensions,  admit  of  no  proof, 
128. 


Apprehensions,  safe    assumptions  Attributes,  extrinsic,  79. 


regarding,  130. 
Apprehensions,  errors  regarding, 

131,  132. 

Approximation,  method  of,  88. 
Archaeology,  definition  of,  340. 
Arguments,  nature  of,  68,  69. 

"          modes  of  testing,  68- 

70,  137-139,  146,  147,  264,  265. 
Arguments,  illustration  of,  69. 

"          by  what  invalidated, 

251. 


Aristotelians,  their  division  of  a  Beings,  definition  of,  58. 


proposition,  Note  2,  435. 

Aristotelians,  their  doctrine  of  rea- 
soning and  the  syllogism,  Note 
5,  436,  437. 

Aristotle's  Categories,  Note  18, 
442. 

Arithmetic,  definition  of,  333. 
"          its  uses,  346. 

Art,  definition  of,  339. 
"  various  kinds  of,  340. 
"   characteristics    and    founda- 
tions of,  392,  3.93. 

Art,  requisites  to  proficiency  in," 
393. 

Art,  how  related  to  Theory,  393, 
394. 

Art,  field  for  improvements  in, 
Note  31,  448. 

Association  of  Thoughts  (see 
Thoughts). 

Assuming  conditions,  paralogism 
of,  277. 

Assuming  the  question,  paralogism 
of,  267,  268. 

Astronomy,  definition  and  divis- 
ions of,  335. 

Astronomy,  character  and  uses  of, 
354. 


Astronomy,  modes  of  establishing  Books,  uses  of,  141,  142,  148. 


its  truths,  354-358. 
Astronomy,  future  discoveries  in, 

Note  24,  443,  444. 
Attention,  nature  of,  34. 


414. 
Attention,  mnemonic  law  and  rules 

of,  413-415. 
Attraction  of  gravitation,  remarks 

on,  Notes  8  and  15,  437, 440. 


intrinsic,  79-85. 
Authority,  fallacies  of  appeals  to, 

316-320. 
Authorship,  how  ascertained,  229- 

232. 
Axioms,  mathematical,  what  they 

are,  345. 

B. 

Begging  the  question,  paralogism 
of,  266-267. 


60. 


various  kinds  of,  58. 
principles   regarding,  58- 


Beings,  how  existence  and  prop- 
erties of  some  known,  75-85. 

Belief,  definition  of,  49. 

"      how     distinguished     from 
knowledge,  30,  49. 

Belief,  common  error,  315. 

Bias,  its  sources,  and  influence  on 
testimony,  214,  215,  217. 

Bias,  how  its  presence  may  be  as- 
certained, 215,  216. 

Biblical   Theology,  definition    of, 
338. 

Biblical  Theology,  foundations  and 
uses  of,  379. 

Biblical  Theology,  study  of,  379- 
381. 

Biography,   definition    and   divis- 
ions of,  341,  343. 

Biography,  how  related  to  History, 
403. 

Biography,  its  uses,  403,  404. 

"         common  defects  in,  404. 

Body,  definition  of,  62. 

"     natural   tendency  of,   170, 
179. 


selection  of,  149,  150. 

study  of,  150,  151. 
"     means  of  ascertaining  their 
origin,  233. 


INDEX. 


451 


Botany,  definition  and  divisions  of, 

336. 
Botany,  sources  and  uses  of,  364. 

C. 

Calculus,    Infinitesimal,    remarks 

on,  347.     Note  22,  442,  443. 
Categories  of  Aristotle,  Note  18, 

442. 
Causation,  principles    of,   61-63, 

175-177, 180. 

Causation,  sophisms  of,  292-298. 
Cause   and  effect,  mnemonic  law 

of,  420. 
Causes,  definition  of,  61. 

"  *  how  their  nature  known, 

Note  7,  437. 
Causes,  principles  regarding,  61- 

63,  175-177,  180. 
Causes,  necessary  and  contingent, 

165. 
Causes,  inadequate,  166. 

"      uses  of  a  knowledge   of, 

166-169. 
Causes,  important  distinction,  169. 

"       efficient  and  conditional, 

169,  170. 
Causes,  immediate,  mediate,  and 

ultimate,  170. 
Causes,  only  ultimate  causes,  170, 

180. 
Causes,  frequent  error,  170. 

"      modes  of  determining,  171 

-175. 
Causes,  criterions  where  these  fail, 

175-177. 
Causes,  sole  and  joint  causes,  177, 

178. 

Causes,  uses  of  analogy,  178. 
"         "   of  experiments,  178, 

179. 
Causes,  new  agencies,  179. 

"      chain  of  causes,  179,  180. 
"      reactive  agencies,  181. 
"      cautions,  181,  297. 
"      fallacies  regarding  causes 

292-298. 

Causes,  distinct  from  laws,  295. 
Certainty,  foundations  of,  45-48. 
"         how  distinguished  from 

probability,  44,  301,  435. 
Chain  of  reasoning,  definition  of,  65 
Chain  of  reasoning,  illustration  of, 

66. 


Chain  of  reasoning,  requisites  to 
validity  of,  66. 

hain  of  reasoning,  how  related  to 
arguments,  68,  69. 
hange,  nature  of,  69. 
"       conditions  of,  60. 
"       principles  regarding,  60- 
63,  437. 

haracteristic  marks,  definition  of, 
64. 

hemistry,   definition    and    divis- 
ions of,  337. 

hemistry,  foundations   and  uses 
of,  371,  372. 

Chemistry,  important  distinction, 
371. 

hildren's  testimony,  remarks  on, 
217,218. 
'hronology,  definition  of,  341. 

"          uses  and  foundations 
of,  402,  403. 

Circumstantial  evidence,  211,  212. 
Jlasses,   organic,  formation    and 
naming  of,  241-243,  441,  442. 
Classification,  definition  of,  238. 

"  mental  and  physic- 

al, 238,  239. 
Classification,  how    distinguished 

from  generalization,  238. 
Classification,  main  objects  of  men- 
tal, 239,  240,  417. 
Classification,  principles  of,  240. 

"  chief  rules  of,  240, 

241. 
Classification,  of  organisms,  241- 

244. 

Classification,  application  of  prin- 
ciples, 244,  245. 
Classification,  influence  of  preju- 
dices, 245. 
Cognitions,  definition  of,  30. 

"         test  of,  48,  244-246. 
Combination,   definition   and   use 

of,  69. 

Commemorations,   mnemonic   ef- 
fects of,  425,  426. 
Common-place  books,  use  of,  428. 
Comparison,  definition  and  nature 

of,  101. 
Complex  proposition,  definition  of, 

39. 

Compositions,  modes  of  ascertain- 
ing their  origin  and  character, 
229-237. 


452 


INDEX. 


Compound  proposition,  definition 

of,  39. 
Comprehension  of  terms,  definition 

of,  191. 
Comprehension,  mnemonic  law  of, 

415. 

Comprehensions,  definition  of,  29. 
"  what  learned  bj, 

29,  33,  34. 
Comprehensions,  require  no  proof, 

128. 
Comprehensions,  paralogisms    of, 

269-271. 
Conceptions,  definition  and  nature 

of,  35,  36. 
Conceptions,  always  particular,  98, 

99. 
Conceptions,    their     reality,    how 

known,  128. 
Conclusions,  definition  of,  65. 

"  requisites  to  validity  C 

of,  66,  67. 
Conclusions,  modes  of  testing,  67, 

68,  136-139,  264,  265. 
Conditional  causes,  definition  of, 

169,  170. 
Conditional  proposition,  definition 

of,  39. 
Conflicting  opinions,  aberrancy  of, 

317. 
Confounding    cause    and    effect, 

sophism  of,  293,  294. 
Confounding  different  senses,  para- 
logism of,  283. 

Confounding  means  and  end,  aber- 
rancy of,  316. 
Confusion,  aberrancies  of,  307-31 6. 

"         sophisms  of,  287-289. 
Connective,  definition  of,  51. 

"          various  forms  of,  68. 
"          necessary      character 

of,  Note  5,  436. 
Consciousness,  definition  of,  30. 

"  futile  attempts  re- 

garding, Note  14,  440. 
Contiguity,  mnemonic  law  of,  419, 

420. 
Contingent  connective,  sophism  of, 

300. 
Contingent  knowledge,  nature  of, 

of,  31. 
Contingent    knowledge,    primary 

modes  of  acquiring,  71-93,  96, 

97. 


Contingent    knowledge,    primary 
modes  of  retaining,  93-98. 

Contradictory  propositions,  defini- 
tion of,  38. 

Contraries,  mnemonic  law  of,  422, 
423. 

Contrary  proposition,  definition  of, 
38. 

Controverted  subjects,  remarks  on, 
142,  143. 

Conversation,  its  logical  charac- 
ter, 142. 

Converse  of  a  proposition,  defini- 
tion of,  38. 

Converse  of  a  proposition,  .when 
true,  288. 

Copying,  why  of  little  mnemonic 
value,  428. 

Corruptions  of  written  testimony, 
232,  233. 

ounting  witnesses,  paralogism  of, 
281. 

Cramming,  evils  of,  145,  414,  415, 
431,  432. 

Credulity,  paralogism  of,  281,  282. 

Criterion  of  intuitions,  267. 

of  reasoning,  65-71. 
of  truth,  48. 

Criterions  of  testimony,  213-219. 

Crystalography,  definition  of,  338. 

Curves,  particular  use  of,  91,  92. 

D. 


Dates,  how  ascertained,  402,  403. 

Dead    languages,    how    learned, 
385-389. 

Deciding  by  appearances,  aberran- 
cy of,  311,  312. 

Deciding  by  character,  aberrancy 
of,  309. 

Deciding  by  consequences,  aber- 
rancy of,  309,  310. 

Deciding  by  motives,  aberrancy  of, 
310,  311. 

Deduction,  definition  of,  130. 

"          error  regarding,  Note 
13,  439,  440. 

Deduction,  tests  of,  136,  137. 

Definitions, verbal  and  real,  192. 
"         rules  of  verbal,  192,193. 
"         characteristics  of  good, 
193. 

Definitions,    when   required    and 
when  not,  429. 


INDEX. 


453 


Desires,  principles  regarding,  62, 

63. 
Desires,  aberrancies  of  appeals  to, 

320-324. 

Desultory  habits,  evils  of,  122,  123. 
Determining  conditions,  definition 

of,  60. 
Determining  conditions,  principles 

regarding,  60-63. 
Deviations,  evils  of,  145. 
Dictionaries,  sources  and  uses  of, 

385-389. 
Difficulties,   art   of  surmounting, 

144-146. 

Diminishing   improbability,  soph- 
ism of,  305. 
Diminishing  probability,  sophism 

of,  305. 
Direct  discovery,  nature  of,  154. 

"  "          observations  on, 

155,  156. 
Direct   proof,   definition   of,  134, 

135. 
Discernments,  definition  of,  30. 

"  require    no    proof, 

128. 
Discordant   opinion,   sophism    of, 

301,  302. 
Discovery,  direct,  154-156. 

"         indirect,  154,  156-162. 
"  .    **         usual    course 

of,  159. 
Discovery,  indirect,  chief  difficulty, 

160. 
Discrepancies  in  testimony,  220- 

222 
Disjunctive  proposition,  definition 

of,  39. 

Disposition  proper  for  investiga- 
tion, 119-121. 

Division,  nature  of,  239,  240. 
Dogmatism,  character  and  origin 

of,  119, 120. 
Duration,  principles  regarding,  53, 

54. 
Duration,  errors  regarding,  Note 

6,  437. 
Dynamic,  definition  of,  334. 

E. 

Education,  definition  of,  340. 

"  its    importance,   395, 

396. 
Effects,  definition  of,  61. 


Effects,  how    distinguished    from 

consequents,  61. 
Effects,  principles  regarding,  61-63. 

"      importance     of    knowing, 

166-169. 
Effects,  how  sometimes  discovered, 

167,  168. 

Effects,  peculiar  use  of,  169. 
"       modes  of  tracing,  171-1 81. 
"       important  principle,  180. 
"       reactive  effects,  181. 
"       cautions,  181,  297. 
Efficient  causes,  definition  of,  169,'* 

170. 
Electric,  definition  and  divisions 

of,  335,  336. 
Electric,  foundations  and  uses  of, 

361. 

Electricity,  probable  nature  of,  362. 
Electrodynamic,  definition  of,  335, 

336. 
Electrodynamic,    importance    of, 

361. 
Electromechanism,  •  definition  of, 

336. 

Electromechanism,  uses  of,  361.      * 
Electrostatic,  definition  of,  335. 

"  importance  of,  361. 

Emotional  arts,  nature  of,  340. 
Emotions,  definition  of,  34. 
"         what  known  by,  34. 
"         mnemonic  law  of,  421, 

i22. 
Emotions,  important    distinction, 

422,  432. 
Empiricisms,  definition  of,  101. 


101,312. 


how     formed,    100, 


Empiricisms,  uses  of,  108. 


109. 


not  laws  of  nature, 


Enemies'  opinions,  sophism  of,  303. 

Epochs,  principal  used,  Note  32, 
448. 

Equanimity,  advantages  of,  119, 
122,  430. 

Equanimity,  its  influence  on  re- 
membrance, 430. 

Equanimity,  how  to  be  secured, 
432. 

Equivocation,  paralogism  of,  27G. 

Eras  (see  Epochs). 

Errors,  sources  of,  45-48,  131, 
132. 


454 


INDEX. 


Errors,  means  of  avoiding,  46-49, 

71-75,  261-265. 
Errors,  why  powerful,  260. 
Essential  properties,  definition  of, 

64, 242.  • 

Ether,  nature  and  probable  effects 

of,  335. 
Ethereal  sciences,  definition  and 

divisions  of,  335,  336,  342. 
Ethereal  sciences,  nature  and  uses 

of,  358. 
^Ethereal  sciences,  probable  origin 

of  their  phenomena,  362 ;  Note 

25,  444,  445. 
Ethic,  definition  of,  338. 

"      foundations  and    uses    of, 

381,  382. 

Ethic,  study  of,  382,  383. 
Ethnology,  definition  of,  336-366. 
Ethnography,  definition  and 

ions  of,  339,  340,  343. 
Ethnography,  foundations  and  uses 

of,  391,  392. 
Ethnography,  why    distinguished 

from  Geography,  Note  20,  442. 
'  Etymologies,  paralogism  of  follow- 
ing, 284. 
Evidence,  definition  of,  129. 

"        general    principles    of, 

209-212. 

Evidence,  signs,  129,  209,  210. 
"        testimony,  129,  210. 
"        concurring,  210,  211. 
"        circumstantial,  211, 212. 
"        criterions  of  testimony, 

212-219. 
Evidence,  concurring  testimonies, 

219. 

Evidence,  discrepancies,  220-222. 
' '        probable  testimony,  222- 

224. 
Evidence,  influence  of  prejudices, 

223,  224. 
Evidence,  futile  distinctions,  225, 

226. 

Evidence,  various  kinds  of  testi- 
mony, 226-228. 
Evidence,  written  testimony,  227- 

237. 

(See  Signs,  and  Testimony.) 
Exaggerating  improbability,  soph- 
ism of,  305. 
Exaggerating  probability,  sophism 

of,  304,  305. 


Excluding  causes,  sophism  of,  296. 
"         effects,  sophism  of,  297. 

Exclusion,  principles  of,  63-65. 

Existence  of  self,  how  known,  75. 

Experiments,  definition  of,  90. 

"  uses  and  objects  of, 

90,  91. 

Experiments,  two  kinds  of,  90. 

rules  regarding,  161. 

Explicit  testimony,  226. 

Expressions,  importance  of  attend- 
ing to,  143,  144. 

Expressions,  rules  of  proper,  190, 
191. 

Expressions,  five  classes  of,  200, 
201. 

Extension,  method  of,  88,  89. 

or  Space,  principles  re- 
lating to,  53,  54. 

divis-  Extension  or  Space,  errors  regard- 
ing, Note  6,  437. 

Extension  of  terms,  definition  of, 
191. 

External  signs,  97,  98. 

Extracts,  uses  of,  428,  429. 

"        how    used    in    remem- 
brance, 425-427. 

Extrinsic  probability,  remarks  on, 
224. 

Extrinsic  properties,  79. 


Faculty,  definition  of,  32. 
Fallacies,  definition  of,  249. 
"        operation  of,  249. 
evils  of,  249,  250. 
"        three  classes  of,  250. 
"        universal  defect  in,  250. 
"        independent  of each  oth- 
er, 251. 

Fallacies,  illustration  of,  251. 
"        sources  of,  252-254. 
"        effects  of  prejudices  on, 
254-260. 
Fallacies,     means     of     guarding 

against,  261-265,  324. 
Fallacies,  common  error,  266. 

"        table  of,  325-327. 
(See    Paralogisms,     Sophisms, 

and  Aberrancies.) 
Fallacious  implication,  paralogism 

of,  286. 

Fallacious    propriety,  paralogism 
of,  286. 


INDEX. 


455 


False  association,  paralogism  of, 

274. 
False  cause,  sophism  of,  292,  293. 

"     effect,  sophism  of,  293 
Falsehood,  paralogism  of,  278. 
Families,  organic,  formation  and 

naming  of,  243,  441,  442. 
Fiction,  how  to  be  detected,  237, 

402. 
Figurative  expressions,  abuse  of, 

196. 
Figurative    interpretation,    when 

proper,  201,  202. 
Figures,  Aristotelian,  remarks  on, 

Note  5,  437. 

Flattery,  why  powerful,  259,  260. 
Following  etymologies,  paralogism 

of,  284. 
Force,  definition  of,  59. 

"     principles    regarding,    59, 

61-63. 

Forgetfulness,  paralogism  of,  275. 
Forgetting,  nature  of,  97. 
Fraud,  chief  source  and  support 

of,  21,  22. 

Friends'  opinions,  sophism  of,  299. 
Futurity,  why  often  undervalued, 

257,321. 
Futurity,  extent  and  importance 

of  our  knowledge  of,  405,  406. 
Futurity,  sources  of  such  knowl- 
edge, 34,  406-410. 

* 

G. 
Galvanism,  definition  of,  336. 

"         importance  of,  361. 
Gases,  characteristic  of,  335-354. 
Genera,  formation  and  naming  of 

organic,  241-243,  441,  442. 
General  belief,  aberrancy  of,  317. 
"       Geography,  definition  of, 

337. 
General  Geography,  sources  and 

uses  of,  368-370. 
General  Grammar,   definition  of, 

339. 

General  Grammar,  uses  of,  391. 
"       proposition,  definition  of, 

39. 

General  terms,  uses  of,  36,  190. 
"  "      what  they  denote, 

99. 
Generalization,     definition      and 

kinds  of,  36,  98. 


generalization,  uses  of,  99. 

various    processes 
of,  99-107. 

ueneralization,  superior  and  sub- 
ordinate laws  of,  107. 

generalization,  uses  of  empirical, 
108. 

uenerulization,  advantages  of  ex- 
tending, 108,  109. 

Generalization,  how  distinguished 
from  classification,  238. 

Generalization,  sophisms  of,  289- 
292. 

Generalization,  its  influence  on  re- 
membrance, 415,  416. 

Geognosy,  definition  of,  337. 

"          sources   and  uses   of, 
370. 

Geographical   sciences,  definition 
of,  334. 

Geographical  sciences,  divisions  of, 
337,  338,  342. 

Geographical    sciences,   character 
and  study  of,  367,  368. 

Geography,  definition  and  divis- 
ions of,  337. 

Geography,  sources   and  uses  of, 
368-371. 

Geology,  definition  and  divisions 
of,  337. 

Geology,  foundations  and  uses  of, 
372,  373. 

Geology,  defects  of,  Note  27,  445. 

Geometry,  definition  and  divisions 
of,  333,  334. 

Geometry,    how    connected    with 
Analysis,  345,  346. 

Geometry,  uses  of,  346,  347. 

God  (see  Theology). 

Grammar,   sources   and   uses   of, 
385-388. 

Gravitation,  law  of,  170. 

"  objectionable  views  of, 

Notes  8  and  15,  437,  440. 

Gravitation,  how  established,  356. 
"  inferences  from,  356- 

358. 

Gravitation,  probable  origin  of  its 
phenomena,  Note  25,  444, 445. 

II. 

Habits,  influence  of,  121,  418. 
"       various  kinds  of,  121-126. 
; '       two  important  laws  of,  1 25. 


456 


INDEX. 


Habits,  how  good  to  be  formed, 

127,  431. 
Harmonizing  conclusions,  sophism 

of,  300. 
Health,  its  importance,  148,  153, 

418,  430. 
Health,  how  to  be  secured,  148, 

365,  366,  432,  433. 
Health,  its  influence  on  remem- 
brance, 418,  430. 
Hearing,  how  aided,  90. 
Hearsay    evidence,    remarks    on, 

216,  226,  227. 
Heat,  importance  of  knowing  its 

laws,  360. 
Heat,  probable  nature  of,  362,  444, 

445. 
History,  definition  and  divisions  of, 

341-343. 
History,  foundations  and  uses  of, 

396,  397,  400. 

History,  boundaries  of,  397,  398. 
"        first  merit  of,  399. 
"        frequent  imperfections  in, 
399,  400. 

History,  two  kinds  of,  399,  400. 
*'        study  of,  400,  401. 
"        traditional,  401,402. 
Homonymous    expressions,    aber- 
rancy of,  314. 
Hurry,  evils  of,  431. 
Hydric,  definition  and  divisions  of, 

334,  335. 
Hydric,  foundations  and  uses  of, 

353. 
Hydrodynamic,  definition  of,  335. 

"  uses  of, 

Hydrology,  definition  of,  337. 

"          sources  and  uses  of,371. 
Hydromechanism,definitionof,335. 

"  uses  of,  353. 

Hydrostatic,  definition  of,  335. 

"          uses  of,  353. 
Hygiene,  definition  of,  336. 

"        importance  of,  366. 
Hypotheses,  definition  of,  109. 

uses  of,  110-112,  159. 
"          why   often   underval- 
ued, 110. 
Hypotheses,  abuse  of,  112,  113. 

"          modes  of  testing,  113- 
115. 

Hypotheses,  peculiarities  of  a  cer- 
tain class  of,  113. 


Hypotheses,  phenomenal,  113.-115. 
refutation    and    con- 
firmation of  these,  114. 

Hypotheses,  preferable,  115,  159. 
common  errors,  115. 

Hypothetical  causes,  sophism  of, 
294. 

Hypothetical   proposition,   defini- 
tion of,  39. 

Hypothetical  truths,  nature  of,  31. 

I. 

Ideas,  definition  of,  33. 

"      distinctions  of,  46,  47. 

"     trains  of,  how  traceable,  419 

-421. 
Identical  proposition,  definition  of, 

38. 
Identity,  personal,  remarks  on,  93, 

94,  132. 
Idioms,  definition  of,  195. 

"      interpretation  of,  204,205. 
Ignorance,  evils  of,  15-25. 
Ignorant    interpretation,    paralo- 
gism of,  285. 

Illusions,  nature  of  spectral,  72. 
Illusive   contradiction,   aberrancy 

of,  315. 
Illusive  sign,  paralogism  of,  271- 

273. 
Imaginary  absurdity,  sophism  of, 

304. 

Imaginary  apprehension,  paralo- 
gism of,  274. 

Imaginary  cause,  sophism  of,  296. 
"  effect,  sophism  of,  297. 
"  quantities,  nature  of, 

350. 
Imaginary    universality,    sophism 

of,  292. 
Imagination,  nature  of,  35,  36. 

misapplications     of, 

255,  305. 
Imitations,  how  distinguished,  131, 

132. 
Immaterial  substances,  definition 

of,  58. 

Immediate  cause,  definition  of,  170. 
Immediate   knowledge,  definition 

of,  30. 
Immediate  testimony,  definition  of, 

226. 
Implications,  difficulty  regarding, 

207,  208. 


INDEX. 


457 


Implicit  testimony,  226. 

Imponderable   substances,    defini- 
tion of,  334. 

Imponderable  substances,  probable 
nature  of,  362. 

Impossible   quantities,  nature   of, 
350. 

Impostors,  on  what  chiefly  depend- 
ent, 21,  22. 

Inanimate  substances,  remarks  on, 
58,  59. 

Inattention,  how   the   immediate 
source  of  error,  48,  49,  252,  253. 

Inattention,  evils  of  habitual,  122. 
causes  of,  253,  254. 

Inclusion,  principles  of,  63-65. 

Incomprehensible  connective,  soph- 
ism of,  300,  301. 

Incomprehension,  paralogism   of, 
270,  271. 

Inconclusive    investigation,   soph- 
ism of,  301 . 

Indefinite    proposition,    definition 
of,  39. 

Indefinite  terms,  aberrancy  of,  307, 
308. 

Index,  uses  of  a  general,  428,  433. 

Indications  (see  Signs). 

Indirect  discovery,  nature  of,  154. 
"  various  observ- 

ations on,  157-162. 

Indirect  pi-oof,  definition  and  char- 
acter of,  134,  135. 

Indiscrimination,   paralogism    of, 
282. 

Individual    proposition,  definition 
of,  39. 

Indolence,  evils  of,  125,  126. 

Induction,  definition  of,  101. 
"  requisites  to,  101. 
' '  various  processes  of,  1 0 1 


Induction,  on  what  based,  104, 105. 
"        how    established,  106, 
107. 

Induction,  uses  of,  108,  393. 

"        advantages  of  extend- 
ing, 108,  109. 

Induction,  aided  by  classification, 
239. 

Induction,  errors  regarding,  Note 
13,  439,  440. 

Inductive  Logic,  remarks  on,  Note 


13,  439,  440. 


Inertia,  remarks  on,  83. 
Inferences,  definition  of,  29,  50,  51 . 
' '         requisites  to  validity  of, 

47,  66,  136-138. 
Inferences,  how  distinguished,  48. 
"         from    comprehensions, 

129-134. 
Inferences,  from  probabilities,  136. 

"         from  testimony,  216. 
Inferring  hypotheses,  sophism  of, 

298,  299. 
Inferring  the  agreeable,  aherrancy 

of,  321. 
Inferring  the  converse,  sophism  of, 

288. 
Inferring  the   probable,   sophisms 

of,  298-301. 
Infinitesimal  Calculus,  re  marks  on, 

347,  Note  22,  442,  443. 
Information,  best  sources  of,  117. 
Inorganical  Sciences,  definition  of, 

334. 

Intellect,  definition  of,  71. 
Intentional    sense,    when    to    be 

adopted,  203. 
Internal  signs,  97. 
Interpretation,  nature  and  use  of, 

200. 
Interpretation,  objectionable  view 

of,  Note  16,441. 
Interpretation,    what    expressions 

require,  200,  201. 
Interpretation,   various    rules    of, 

201-207. 
Interpretation,  frequent  sources  of 

difficulty,  207,  208. 
Interpretation,  use  of  translations, 

208. 

Interpretation,  influence  of  preju- 
dices, 208. 
Interpretation,  fallacies    of,  278- 

280. 

Interrogation,  paralogism  of,  277. 
Intervals,  mnemonic  law  of,  416. 
Intrinsic  probability,  remarks  on, 

224. 

Intrinsic  qualities,  79-85. 
Intuitions,  definition   and   nature 

of,  29,  47,  64. 
Intuitions,  knowledge  obtained  by, 

49. 
Intuitions,  admit  of  no  proof,  127, 

128. 
I  Intuitions,  paralogisms  of,  266,267. 


u 


458 


INDEX. 


Intuitions,  criterion  of,  47,  267. 
Intuitional  assumption,  paralogism 

of,  266,  267. 
Intuitional    rejection,   paralogism 

of,  266,  267. 
Invention,  nature  of,  154. 

"        how  related  to  indirect 

discovery,  162. 
Invention,  two  kinds  of,  162. 

"        principal  fields  of,  162, 

163. 
Invention,   requisites   to    success, 

163,  164. 

Invention,  various  aids  in,  164. 
Investigation,  dispositions    affect- 
ing, 119-121. 
Investigation,  habits  affecting,  121 

-127. 
Investigation,  requisites  to  success, 

120, 121,  318. 
Investigation,  evils  of  superficial, 

124.     (See    Proof,   Study,  and 

Original  Investigation.) 
Irrelevant  admission,  aberrancy  of, 

319,320. 
Irrelevant  analogies,  aberrancy  of, 

308,  309. 
Irrelevant    empiricism,  aberrancy 

of,  312. 
Irrelevant    illustration,  aberrancy 

of,  307. 
Irrelevant  induction,  aberrancy  of, 

312. 
Irrelevant  modification,  aberrancy 

of,  314. 
Irrelevant  objection,  aberrancy  of, 

313. 

J. 

Judgements,  definition  of,  71. 

"          other  views  of,  Note 
9,  437,  438. 

Jurisprudence, definition  and  divis- 
ions of,  338,  339. 

Jurisprudence,     nature,     founda- 
tions and  uses  of,  383,  384. 

Jurisprudence,  study  of,  385. 

K. 

Knowable,  boundaries  of  the,  30. 
Knowledge,  definition  of,  30. 

"          advantages  of,  15-25. 

"          requisites  in  its  pur- 
suit, 16,120,  121,318. 


Knowledge,  its  limits,  29,  30. 

"          its  threefold  division, 
29. 
Knowledge,  how  distinguished  from 

belief,  30,  265. 

Knowledge,  immediate  and  medi- 
ate, 30,  31. 
Knowledge,  necessary,  contingent, 

and  hypothetical,  31. 
Knowledge,  of  real  beings,  on  what 

founded,  71. 
Knowledge,  mental  processes  for 

acquiring,  75-85. 
Knowledge,  external  processes  for 

acquiring,  86-93. 

Knowledge,  primary  modes  of  re- 
taining and  perpetuating,  93-98. 
Knowledge,  primary  and  second- 
ary, 139,  140. 

Knowledge,  best  sources  of,  147. 
"          no  royal  road  to,  149. 
test  of  its  amount,  19 1 . 
"          table  of  the  means  of 
acquiring,  246. 

Knowledge,  classification  of,  331. 
<;          scientific,  331-339. 
"          mixed,  339,  340. 
"          particular,  340,  341. 
"          table  of,  341-343. 
"          of  futurity,  405-410. 
"          retention  of,  by  simple 
remembrance,  413-425. 
Knowledge,  retention  of,  by  exter- 
nal signs,  425-429. 
Knowledge,  requisites  to  a  ready 

command  of,  429,  430. 
Knowledge,  means  of  acquiring  and 

employing  these,  431-433. 
Knowledge,  table  of  the  means  of 

retaining,  434. 
Known,  boundaries  of  the,  30. 


Language,  how  related  to  reason- 
ing, 70,  71. 

Language,  vernacular,  how  learn- 
ed, 85. 

Language,  importance   of  under- 
standing, 144,  315. 

Language,  origin  of,  182,  183. 

progress  of,  183-188. 
"         compounding      terms, 
whence,  185,  186. 

Language,  not  of  divine  origin,  188. 


INDEX. 


459 


Language,  uses  of,  189. 
"         natural,  189. 
"         advantages  of  speech, 
189,  190. 

Language,  three  rules  of  proper  ex- 
pression, 190, 191. 

Language,  definitions,  192,  193. 

"         new    terras,  when    re- 
quired, 193,  194. 

Language,  new  terms,  when  to  be 
avoided,  194. 

Language,  what  it  represents,  194. 
"         imperfections    of,  195, 
19G. 

Language,  abuses  of,  196-199. 

"     •    interpretation  of,  200- 
208.     (See  Interpretation. ) 

Language,    misinterpretation    of, 
283-287. 

Language,  modes  of  learning,  385 
-389.     (See  Philology.) 

Law  (see  Jurisprudence). 

Laws  of  habits,  125. 

Laws  of  health,  advantages  of  at- 
tending to,  148, 153. 

Laws  of  motion,  59,  443. 

"  proposed  addition 

to,  Note  23,  443. 

Laws  of  nature,  how  established, 
101-107. 

Laws  of  nature,  superior  and  sub- 
ordinate, 107. 

Laws  of  nature,  advantages  of  ex- 
tending, 108,  109. 

Laws  of  nature,  distinguished  from 
empiricisms,  109. 

Laws  of  nature,  what  they  are, 
109,  170. 

Laws   of   nature,  importance   of 
knowing,  166, 168,  173,  174. 

Laws  of  nature,  not  efficient  causes, 
295. 

Laws  of  nature,  their  uniformity 
and  permanence,  407-409. 

Laws  of  remembrance,  413-425. 

Lectures,  characteristics  of,  142. 

Letters,  origin  and  spread  of,  Note 
12,  438,  439. 

Life,  criterion  of,  364. 

Light,  probable  nature  of,  359, 360. 

Likenesses,  different  kinds  and  uses 
of,  97,  98,  426,  438. 

Likenesses,  how  subservient  to  re- 
membrance, 93-95,  96-98,  426. 


Lines,  mathematical,  property  of, 

54. 

Liquids,  definitions  of,  334,  353. 
Literal  int3rp  Fetation,  when  proper, 

and  when  not,  201-203. 
Logic,  definition  of,  13. 

"     objectionable  definition  of, 

Note  1,  435. 
Logic,  nature  and  foundations  of, 

13. 
Logic,  its  proper  limits,  14. 

u      its  objects  and  uses,  14,  15. 

"      study  of,  15. 

"      remarks    on    Aristotelian, 

Note  5,  436,  437. 
Logic,  error  regarding,  Note  13, 

439, 440. 
Logic,   how    distinguished    from 

Psychology,  376. 

M. 

Magnetism,  definition  of,  336. 

"         foundations  and  uses 
of,  361. 

Magnitudes,  principles  regarding, 
54-58. 

Mannerism,  remarks  on,  205. 

Manuscripts,  means  of  ascertain- 
ing their  origin,  231,  233. 

Manuscripts,  tests  of  their  authen- 
ticity, 232,  233. 

Manuscripts,  sources  of  errors  in, 
234. 

Manuscripts,  means   of  removing 
sources  of  errors  in,  235-238. 

Many  arguments,  aberrancy  of,  319. 

Mass,  definition  of,  Note  23,  443. 

Mathematical  Geography,  defini- 
tion of,  337. 

Mathematical  Geography,  founda- 
tions and  uses  of,  368-370. 

Mathematics,  definition  and  divis- 
ions of,  333,  334,  341. 

Mathematics,  peculiarities  of,  344- 
346. 

Mathematics,  errors  regarding, 344. 
uses  of,  346,  347. 
study  of,  347-350. 
*'          effects    of   exclusive 
study  of,  350,  35 1 . 

Matter,  definition  of,  58. 

"  principles  regarding,  58-60. 
"  its  natural  tendency,  170, 
179. 


460 


INDEX. 


Matter,  two  kinds  of,  334. 
Measurement,  various   modes   of, 

87,  89. 

Measures,  standard  of,  87. 
Mechanic,  definition  and  divisions 

of,  334. 
Mechanic,  foundations  and  uses  of, 

352,  353. 
Mechanical   properties,  definition 

of,  334. 
Mechanical  sciences,  definition  and 

divisions  of,  334,  335,  342. 
Mechanical  sciences,  foundations, 

uses  and  study  of,  352-358. 
Mechanism,  definition  of,  334. 
Mediate  causes,  definition  of,  170. 
"       knowledge,  definition  of, 

30. 

Mediate  knowledge,  how  establish- 
ed, 34,  93-98,  129. 
Mediate  testimony,  226,  227. 
Medical  arts,  rational  bases  of,  3GG, 

367. 
Memory,  definition  of,  33. 

uses  of,  71,  93,  96. 
"        reliability  of,  93-95. 
"        primary  processes  of, 

95,  96-98. 
Memory,  means   of  avoiding   its 

primary  errors,  95,  96. 
Memory,  recognition,  95,  96. 
"        use  of  similitudes,  97. 
"       safe  assumptions  regard- 
ing, 132. 
Memory,  sources  and  safeguards 

of  error,  132,  133,216,  217. 
Memory,  how  aided  by 

tion,  239,417. 
Memory,  paralogisms  of,  274,  275. 

(See  Remembrance.) 
Mendacity,  paralogisms   of,  278- 

280. 
Mental  discipline,  advantages  of, 

23,  24,  374,  375. 
Mental  sciences,  definition  and 

visions  of,  338,  339,  342,  343. 
Mental  sciences,  characteristics  of, 

374. 
Mental  sciences,  foundations  anc 

uses  of,  374,  375. 
Mental    sciences,  study    of,  375. 

376. 
Metaphysics,  remark  on,  Note  28 

446. 


Meteorology,  definition  of,  337. 

sources  and  uses  of, 
371. 

lethod  (see  System). 

VIethodical  habits,  advantages  of, 
122,  123. 

Vlicroscope,  uses  of,  90,  362,  363. 

Vlind,  usual  tendency  of,  265,266. 

Mineralography,  definition  of,  338. 

Mineralogy,  definition  and  divis- 
ions of,  338. 

Mineralogy,  uses  and  sources  of. 
372. 

Miscomprehension,  paralogism  cf, 
269,  270. 

Misconception,  paralogism  of,  285, 
286. 

Misconstruction,paralogismof,285. 

Misinterpretation,  sources  of,  207, 
208. 

Misinterpretation,  paralogisms  of, 
283-287. 

Misinterpreting  ambiguities,  paral- 
ogism of,  283. 

Misinterpreting  technicalities,  pa- 
ralogism of,  283. 

93-  Misplacing  the  accent,  paralogism 
of,  284,  285. 

Misrepresentation,  paralogisms  of, 
278,  279. 

Misrepresenting  comprehensions, 
paralogism  of,  279. 

Misrepresenting  testimony,  paral- 
ogism of,  279,  280. 

Mistaking  allusions,  paralogism  of, 
286. 

istaking  expressions,  paralogism 
of,  283. 

Mistaking  ideas,  paralogism  of, 
274,  275. 

Mistaking  the  chief  cause,  sophism 
of,  294. 

Mistaking  the  chief  effect,  sophism 

of,  294. 

di  Mistaking    the    ultimate     cause, 
sophism  of,  295. 

Mistaking  the  style,  paralogism  of, 
284. 

Misunderstanding  archaisms,  pa- 
ralogism of,  283. 

Mixed  knowledge,  definition  and 
divisions  of,  339,  340-343.  (See 
Philology,  Ethnography,  and 
Technology.) 


classifica-  M 


INDEX. 


461 


Mnemotechny,  character  of,  423. 
Modern    opinions,  aberrancy    of, 

317. 
Momentum,  definition  of,  Note  23, 

443. 
Monuments,  mnemonic  use  of,  425, 

426. 
Moods,  remarks   on   Aristotelian, 

Note  5,  437. 
Moral  certainty,  nature  of,  Note  3, 

435. 
Morality,  definition  of,  338. 

"         foundations  and  import- 
ance of,  381,  383. 
Morality,  study  of,  382,  383. 
Mortifying  proofs,  sophism  of,  303. 
Motion,  natm-e   and  laws   of,  59, 

Note  23,  443. 

N. 

Natural  History  (see  Zoology). 
"        Theology,  definition    of, 
338. 

Natural  Theology,  foundation  and 
importance  of,  378,  379. 

Natural  Theology,  study  of,  379. 

Nature,  laws  of,  how*established, 
101-107. 

Nature,  laws  of,  superior  and  sub- 
ordinate, 107. 

Nature,  laws  of,  advantages  of  ex 
tending,  108,  109. 

Nature,  laws    of,    distinguishable 
from  empiricisms,  109. 

Nature,   laws    of,   importance    of 
knowing,  166,  168,  173,  174. 

Nature,  laws  of,  not  efficient  caus- 
es, 295. 

Nature,  hypothesis  regarding,  Note 
25,  444,  445. 

Nature,  uniformity    and    perma- 
nence of,  407-409. 

Necessary    implication,   definition 
of,  29. 

Necessary  qualities,  principles  re- 
garding, 58-60. 

Necessary   truths,  nature   of,    29 
31. 

Negative  proposition,  definition  of, 
39. 

Negative     quantities,  nature    of 
348,  349. 

Nervous   system,  its  influence  01 
remembrance,  418. 


!^ew  words,  remarks  on,  193,  194. 

!tfon-interpretation  of  signs,  paral- 
ogism of,  273,  274. 

Nosology,  definition  of,  336. 

Motions,  definition  of,  33. 

lumbers,  principles  regarding.  54- 
58. 

Numbers,  abstract  and  concrete, 
349. 

O. 

Objection,  paralogism  of  irrele- 
vant, 313. 

Obscure  expression,  paralogism  of, 
277. 

Obscurity,  means  of  avoiding,  191. 
"        sources  of,  196-198. 

One-sided  arguments,  sophism  of, 
299,  300. 

Ontology,  why  not  a  science,  Note 
28,  445,  446. 

Opinion,  definition  of,  49. 

Optic,  definition  of,  335. 

"     foundations    and    uses    of, 
358-360. 

Oral  testimony,  observations  on, 
227  228. 

Orders,  formation  of  organic,  242, 
243. 

Orders,  naming  of  organic,  243, 
441,  442. 

Ordinary  significations  of  words, 
when  to  be  adopted,  and  when 
not,  201-203. 

Organic  species  and  genera,  prop- 
erties of,  105,  106. 

Organic  species  and  genera,  nam- 
ing of,  243,  441,  442. 

Organic  specimens,  means  of  pre- 
serving, Note  26,  445. 

Organical  sciences,  definition  of, 
334. 

Organical  sciences,  divisions  of, 
336,  337,  342. 

Organical  sciences,  characteristics 
and  study  of,  362,  363. 

Organical  sciences,  guiding  prin- 
ciples in,  363,  364. 

Organisms,  classification  of,  241- 
244. 

Original  investigation,  151-164. 

"  "  the  gener- 

al character  of,  151. 

Original  investigation,  uses  of,  1 52. 


462 


INDEX. 


Original  investigation,  selection  of 

subjects,  153. 
Original    investigation,  prerequi- 


Pathology,  definition  and  divisions, 

336,  337. 
Pathology,  uses  of,  366,  367. 

two   important   princi- 


sites  to,  153,  154. 
Original  investigation,  methods  of,      pies,  357. 

154,  155.  jPathology,  foundations  of,  357. 

Original  investigation,  the  pririci-  Peculiar  marks,  definition  of,  64. 

pal  rules  of,  155.  Perception,  definition  of,  32. 

Original  investigation,  direct  dis-  Perseverance,  advantages  of,  125. 


Personal  identity,  nature  and  proof 

of,  93,  94, 132. 
Personal  observations,  advantages 


covery,  155,  156. 

Original  investigation,  indirect  dis- 
covery, 156-162. 

Original   investigation,  invention, 

162-164.  Perspicuity, how  to  be  secured,  191. 

Overlooking     conditions,    paralo- 'Petrology,  definition  of,  337. 
gism  of,  277.  ! Phantasm,  definition  of,  33. 

Overlooking  testimony,  282.  'Philology,  definition  and  divisions 


the  alternative,  soph- 
ism of,  302. 

Overlooking  the  idiom,  paralogism 
of,  284. 

P. 

Palaeontology,  definition  of,  337. 
Paralogisms,  definition  of,  250. 
"  illustration  of,  251. 


of,  339,  343. 

Philology,  modes  of  learning  a  lan- 
guage, 385-389. 

Philology,  principles  and  results  of 
comparative,  389,  390. 

Philology,  errors  regarding,  Note 
30,  446,  447. 

Philology,  general,  390,  391. 
'  uses  of,  391. 


of  assuming  what  is  Phonetic  writing,  nature  of,  97. 


attempted  to  be  proved,  267- 
269. 

Paralogisms,   of    comprehension, 
269-271. 

Paralogisms,  of  signs,  271-274. 

of  memory,  274,  275. 
"  of  testimony  (intrin- 

sic), 275-280. 

Paralogisms,  of  testimony  (extrin- 
sic), 280-282. 

Paralogisms,  of  misinterpretation, 
283-287. 

Paralogisms,  table  of,  325. 

Particular  knowledge,  nature  of, 
331. 

Particular  knowledge,  divisions  of, 
340,  341,  343. 

(See  History,  Chronology,  and 
Biography.) 

Particular    proposition,  definition 
of,  39. 

Passions,  evil  effects  of,  119,  422, 
430,  432. 

Passions,  distinction,  422, 432. 

"       means    of   moderating, 
432. 

Past,  how  known,  34,  93-98. 


origin  and  spread 

of,  Note  12,438,439. 
Phonetic  writing,  advantages  and 

disadvantages  of,  426,  427. 
Physical   sciences,  definition   and 

divisions  of,  334-338. 
Physical    sciences,  characteristics 

and  study  of,  351. 
Physical  sciences,  uses  of,  352. 

welfare,  requisite  to,  200. 
Physiology,  definition  and  divisions 

of,  336. 
Physiology,  foundations  and  uses 

of,  365,  366. 

Phytology,  definition  of,  336. 
Pictures,  uses  of,  91,  92, 426. 

"       disadvantages     of,    424, 

425,  426. 
Pneumatic,  definition  of,  335. 

"         foundations   and  uses 

of,  353,  354. 
Pneumatology,  remark  on,  Note 

28,  446. 
Point,  property  of  mathematical, 

54. 
Political  Economy,  remarks   on, 

Note  29,  446. 


INDEX. 


463 


Ponderable  matter,  definition  of, 

334. 
Power,  how   its    nature   known, 

Note  7,  437. 

Predicate,  definition  of,  37. 
Prejudices,  evils  of,  126,  208. 
"          rules  regarding,  143. 
"         influence  of,  on  testi- 
mony, 223, 224. 

Prejudices,  influence  of,  on  classi- 
fication, 245. 

Prejudices,  nature  and  general  op- 
eration of,  254-256. 
Prejudices,  causes  of  power  of,  255, 

256,  260. 
Prejudices,  several  kinds  of, 

260. 
Prejudices,  combination  of,  260. 

"         means     of     guarding 
against,  261,262,  265. 
Premise  and  inference,  mnemonic 

law  of,  420. 
Premises,  definition  of,  50. 

"        inaccurate  use  of,  160. 
Primary  premises,  definition  of,  65 
"  "         criterhms  of,  66, 

135-138. 
(See  Reasoning,  Evidence,  anc 

Testimony.) 
Principles  of  reasoning,  50-65. 

"  "      general  prin- 

ciple, 50. 
Principles    of   reasoning,  special 

principles,  52-65. 
Principles    of  classification,  240- 

242. 
Probability,  definition  of,  40. 

"          different  kinds  of, 
43. 
Probability,  general  character  of, 

43,  44,  223,  224. 
Probability,  uses  of,  44,  45. 

resultant,  45. 

"          how        distinguished 
from  certainty,  44,  301,  435. 
Probability,  reasoning  from,  136. 

"          circumstantial,      211, 
212. 

Probability,   effects   of,   on   testi- 
mony, 222-225. 
Probability,  extrinsic  and  intrinsic. 

223,  224. 

Probability,  futile  distinctions)  225 
226. 


Probability,  sophisms  of,  296-306. 
Probable  reasoning,  nature  of,  136. 
Proof,  definition  of,  127,  129. 
"    what  truths  require  none, 
127-129. 

Proof,  twofold  division  of,  129. 
"     what  may  be  admitted  as 
proved,  129-134. 
Proof,  what  propositions  require, 

134. 

Proof,  two  kinds  of,  134,  135. 
"     general  modes   of  testing, 
134-139. 
(See  Deduction,  Evidence,  and 

Testimony.) 
256-  Properties,  extrinsic,  79. 

"          intrinsic,  79-85. 
"         of  organic  beings,  105, 
106. 

Properties,  essential  and  non-essen- 
tial, 242. 

Propositions,  definition  of,  37. 
parts  of,  37,  38. 
"  expression  of,  38. 

Aristotelian  view  of, 
Note  2,  435. 
Propositions,  various  kinds  of,  38, 

39. 

Propositions,  ambiguities  in,  39. 
"  various  forms  of,  40. 

combinations  of,  40. 
Prototype,  definition  of,  33. 
Psychology,  definition  of,  338. 

"  boundaries    of,  376, 

377. 

Psychology,  foundations  and  im- 
portance of,  377. 
40-  Psychology,  study  of,  377. 

Pyrrhonism,  futility  of,  Note  14, 
440. 

Q. 

Qualities,  extrinsic,  79. 
"        intrinsic,  79-85. 

Quantities,  principles    regarding, 
54-58. 

Quantities,  means    of  accurately 
determining,  86-91. 

Quantities,  standards  of,  87. 
"          negative,  348,  349. 

Quantities,  imaginary  or  impossi- 
ble, 350. 

Quantities,  unit  of,  87,  346,  355. 
(See  Mathematics.) 


404 


IXDEX. 


R. 

Ratiocination,    error     regarding, 

Note  13,  439,  440. 
Real  definitions,  nature  of,  192. 
Reason,  definition  of,  33,  49,50. 
Reasoning,  definition  of,  33,49,50. 
"          objectionable  views  of, 
Notes  4,  5,  and  13,  435,  436, 
439,  440. 

Reasoning,  general  principle  of,  50. 
"          identity  of,  in  all  cases, 
50. 
Reasoning,  expression  of,  50,  51. 

"  special   principles   of, 

52-G5. 

Reasoning,  processes  of,  G5-70. 
"          chain  of,  G5,  GG. 
"  requisites   to   validity 

of,  66,  67. 
Reasoning,    ultimate   foundations 

of,  67,  130. 
Reasoning,  modes  of  testing,  67, 

68,  136-139. 

Reasoning,  arguments,  68. 
"          combination,  69. 
"          why  unimpugnable,  70. 
"          how    related    to    lan- 
guage, 70,  71. 
Reasoning,  aids  of,  71. 

"          from  probabilities,  133. 
"          in  a  circle,  paralogism 
of,  268,  269. 

Recognition,  nature  of,  95,  421. 
Recollection,  definition  of,  97. 

"  operation     of,    418, 

419. 
Re-comprehension,  mnemonic  law 

of,  417. 

Recreation,  advantages  of,  148. 
Reductio  ad  abstirdum,  nature  of, 

134,  135. 
Reduction   of  syllogisms,  remark 

on,  Note  5,  437. 

Rejecting  the  disagreeable,  aber- 
rancy of,  321,  322. 
Rejecting    the    improbable,   soph- 
isms of,  301-304. 
Rejecting  theories,  sophism  of, 302. 
Relations  of  thoughts,  nature  and 
general  law  of,  418. 


Relations  of  thoughts,  two  kinds  Results,   how   tested,    in    certain 


of,  419. 

Relations    of   thoughts,    natural, 
419-425. 


Relations  of  thoughts,  remarks  on 
artificial,  423.     (See     Remem- 
brance, and  Thoughts.) 
Religion,  proper   foundation  and 

importance  of,  378. 
Religious  knowledge,  only  reliable 

sources  of,  381. 

Remembrance,  definition  of,  33. 
"  nature  of,  33. 

"  importance  of,  34, 

93,  9G. 

Remembrance,reliability  of,  93-95. 

"  recognition,  95,  9G. 

similitudes,  96,  97. 

"  primary    processes 

of,  93-95,  96-98. 

Remembrance,    safe    assumptions 

regarding,  132. 

Remembrance,  sources  and  safe- 
guards of  error,  132,  133,  216, 
217. 
Remembrance,  general  laws  and 

rules  of,  413-419. 
Remembrance,  laws   of  the  rela- 
tions of  thoughts,  419-425. 
Remembrance,  two 'kinds  of,  419. 
contiguity  and  suc- 
cession, 419-421. 
Remembrance,  resemblance,  421. 
emotions,  421,  422. 
contraries,  422, 423. 
"  various       observa- 

tions on,  423-425. 
Remembrance,     external     signs, 

425-427. 

Remembrance,  writing,  427-429. 
"  requisites  to  readi- 

ness of,  429,  430. 
Remembrance,  how  these  to  be  se- 
cured, 431-433. 

Repetition,  its  influence  on  remem- 
brance, 416. 

Repetition,  method  of,  87,  88. 
combination  of,  89. 
Representations,   uses   of  visible, 

91,  92,  426. 
Representations,  uses  of  tangible, 

92,  93. 

Resemblance,  mnemonic  law  of, 
421. 


cases,  90. 
Retention  of  knowledge,  primary 
processes  of,  96-98. 


INDEX. 


465 


Retention  of  knowledge,  by  simple 

remembrance,  413-425. 
Retention  of  knowledge,  relations 

of  thoughts,  419-425. 
Retention  of  knowledge,  external 

signs,  425-429. 
Retention  of  knowledge,  writing, 

427-429. 

Revelation,  evidences  of,  379. 
"          importance  of,  379. 
"          study  of,  379-381. 
Reviewing,  its  importance  in  study, 

148. 
Reviewing,  mnemonic  laws,  416, 

417, 

Rhetoric,  definition  of,  340. 
"        uses  of,  394,  395. 
Ridicule,    its    logical    character, 

322. 
Rumor,  general  character  of,  226, 

227. 
Rumor,  when  important,  227. 

S. 
Sages' opinions,  aberrancy  of,  317, 

318. 
Scepticism,  character  and  origin 

of,  119,  120. 

Scepticism,  paralogism  of,  282. 
Sciences,  which  dependent  on  ex- 
perience, 137. 
Sciences,  definition  of,  331. 
"       requisites  to,  331,  332. 
"        boundaries  of,  332,  333. 
"       three  classes  of,  333. 
"       remarks  on  some  names 
of,  Note  19,  442. 
Sciences,  table  of,  341-343. 

' '       their  relations  to  Art,  392, 
393. 

Sciences,  permanence  of  (see  Math- 
ematics, Physical  Sciences,  and 
Mental  Sciences). 
Self-control,  advantages    of,   126, 

127. 

Self-indulgence,  evils  of,  126,  127. 
Semeiology,  definition  of,  336,337. 
Sensations,  definition  of,  32. 


Senses,  subsidiaries  of,  86-93. 
Severing  probabilities,  sophism  of, 

302,  303. 
Sight,  how  aided,  90. 

"     cause  of  its  superior  power, 

424,  425. 
Signs,  definition  of,  129. 

"     internal   and   external,   97, 

98,  129. 
Signs,  general  means   of  testing, 

135. 
Signs,  conclusive,  209. 

"     how  these  ascertainable,209. 

"     probable,  209,  210. 

"     value  of,  how  determined, 

210. 
Signs,  use  of,  in  aiding  testimony, 

222,  223. 
Signs,  paralogisms  of,  271-274. 

"     use   of,  in   aiding  remem- 
brance, 425-429. 
Similitudes,  definition  of,  33. 

"          distinctions,  46,47,72, 

73,  96. 

Similitudes,  relation  of,  to  remem- 
brance, 97. 
Similitudes,  how  fading  rendered 

precise  and  vivid,  417. 
Simple  proposition,  definition  of, 

39. 

Singular  proposition,  39. 
Sneers,  logical  character  of,  322. 
Sobriety,  advantages  of,  126,  127, 

418. 

Solid  bodies,  nature  of,  58. 
Solidity,  mathematical,  54,  333. 
"        resistive,  58. 
"        mechanical,  334. 
Solids,  properties  of  mathematical, 

54. 

Sophisms,  definition  of,  250. 
"         illustration  of,  251. 
"         of  confusion,  287-289. 
"         of  generalization,  289- 


with,  432. 
Senses,  credibility  of,  71-75. 

"       origin  of  errors  attributed 

to,  71,  72,  132. 
Senses,  how  to  avoid  these,  72-75. 


Sophisms  of  causation,  292-298. 
'         of  probability,  298-306. 
'         table  of,  326^ 
proper  mode  of  dealing  Sophistical  combination,  sophism 


of,  292. 
Sophistical  connection,  sophism  of, 

287,  288. 
Sophistical    contraction,    sophism 


TJ2 


of,  291. 


4GG 


INDEX. 


Sophistical  distinction,  sophism  of. 

304. 
Sophistical  exclusion,  sophism  of, 

291. 
Sophistical   explanation,   sophism 

of,  295. 
Sophistical  extension,  sophism  of, 

290. 
Sophistical  inclusion,  sophism  of, 

290,  291. 
Sophistical  induction,  sophism  of, 

295. 

Sophistical  leap,  sophism  of,  301. 
"         proof,  sophism  of,  295, 

296. 
Sophistical  relation,  sophism  of, 

296. 
Space,   principles   regarding,   53, 

54. 
Special  interpretation,  when  to  be 

Adopted,  202. 
Species,  classification  of  organic, 

241,  242. 
Species,   mode    of  naming,   242, 

Note  17,  441,  442. 
Speech  (see  Language). 
Specters,  nature  of,  72. 

' '        remarkable  case,  Note  10, 

438. 

Spurious  compositions,  how  distin- 
guished, 230-232. 
Static,  definition  of,  334. 
Straight  line,  principles  regarding, 

56-58. 

Study,  what  acquired  by,  139. 
importance  of,  139. 
general  objects  of,  139,140. 
other  advantages  of,  140. 
order  of,  140. 
selection  of  subjects,  140, 

141. 
Study,  objects  to  be   considered, 

141. 
Study,  extent  of,  141. 

"      three  modes  of,  141,  142. 

"      of    controverted    subjects, 

142,  143. 
Study,  general  rules  of,  143-148. 

"      prejudices,  143. 

' '      meaning  of  terms,  143, 144. 

"      language,  144. 

"       difficulties,  144-146. 

' '      evils  of  deviations  andcram- 

ming,  145. 


Study,  advantages  of  careful  and 

thorough,  146. 
Study,  testing  statements,  146, 147. 

'        sources  of  information,  147. 

'        simultaneous  subjects,  147, 

148. 
Study,  recreation,  148. 

*  laws  of  health,  148. 
'        final  reviewing,  148. 

'        selection  of  books,  148, 149. 
1        of  books,  150,  151. 

*  evil  practices  of,  150,  151. 
'        different  from  reading,  431, 
432. 

Style,  requisites  to  a  good,  190- 

194. 
Subject  of  a  proposition,  definition 

of,  37. 
Substances,  necessary  qualities  of, 

58-60.- 
Succession,  mnemonic  law  of,  419, 

420. 
Superstition,  its  origin  and  remedy, 

22,  23. 
Suppressing  truth,  paralogism  of, 

278,  279. 

Surfaces,  properties  of  mathemat- 
ical, 54. 
Syllogism,  definition  of,  50. 

"        Aristotelian     view    of, 

Note  5,  436,  437. 
Syllogism,  parts  of,  50,  51. 

"        various  modes  of  stat- 
ing, 51. 

Syllogism,  modes  of  testing,  66-70. 
"        error    regarding,    Note 

13,  439,  440. 

Symbolic  writing,  character  of,  98. 
Symbols,  uses  and  kinds  of,  91-98, 

426. 
Symptomatology,  definition  of,  336, 

337. 

Synopses,  uses  of,  264,  417. 
Synthetical    Geometry,  definition 

of,  334. 

Synthetical  Geometry,  uses  of,  350. 
System,  general  advantages  of,  122, 

123,  430. 

System,  mnemonic  law  of,  417,418. 
"      how  secured,  127,  431. 

T. 

Table  of  the  means  of  acquiring 
knowledge.  246. 


INDEX. 


467 


Table  of  fallacies,  325-327. 

"     of  the  principal  branches  of 

knowledge,  341-343. 
Table  of  the  means  of  retaining 

knowledge,  434. 
Tables,  uses  of,  428,  429. 
Tangible  representations,  use  of, 

92,  93. 
Technical  senses,  when  to  be  adopt-  Testimony 

ed,  202. 
Technology,  definition  and  divi 

ions  of,  339,  340,  343. 

l, See  Art.) 
Temperance,  advantages  of,  126, 

127,418. 
Terms,  uses  of  general,  36, 190. 

"     what  these  denote,  99. 

"      importance  of  understand- 
ing, 143,  144. 
Terms,  understanding  of,  how 

effected,  196,  199,  202. 
Terms,  when  new  requisite,  194. 
"     whence  these  best  derived, 

194. 
Terms,  when   new   objectionable, 

194. 

Terms,  five  classes  of,  200,  201. 
Testimony,  definition  of,  129. 
"         safe    assumptions 

garding,  133. 
Testimony,  general  principle  of  its 

credibility,  133,  134,  210. 
Testimony,    two    requisites,  135, 

136. 
Testimony,  influence  of  witness's 

moral  character,  210. 
Testimony,   importance    of,   212, 

213. 

Testimony,  criterions  of,  213-219. 
"         general    and    special, 

213. 
Testimony,  concurring  testimonies, 

219. 
Testimony,  nature   of  the 

ments,  219,  220. 

Testimony,  discrepancies,  220-222. 
"         difficulties,    how    sur- 
mountable, 221,  222. 
Testimony,  probable  testimony,  222 

-224. 
Testimony,  influence  of  prejudices, 

223,  224. 
Testimony,  futile  distinctions,  225, 

226. 


Testimony,  explicit  and  implicit, 

226. 
Testimony,  oral  and  written,  227, 

228. 
Testimony,  effects  of  lapse  of  time, 

228,  237. 

Testimony,  evidences  of  author- 
ship, 229-232. 

,  sources  of  material  cor- 
ruptions, 232. 
divis-  Testimony,  rules  regarding  these, 

232,  233. 
Testimony,  means  of  ascertaining 

origin  of  writing,  233. 
Testimony,  various  readings,  234. 
"         rules  regarding  these, 
235,  236. 
Testimony,  authentic  and  fictitious, 

237. 

to  be  Testimony,  paralogisms  of  (intrin- 
sic), 276-280. 

Testimony,  paralogisms  of  (extrin- 
sic), 280- -282. 
Theology,  definition  and  divisions 

of,  338. 

Theology,  character  and  founda- 
tions of,  377-379. 
Theology,  study  of,  379-381. 
re-  Theory,  definition  of,  114. 

"      its  relations  to  Art,  393, 
394. 
Therapeutic,  definition  of,  337. 

foundations  of,  357. 
Thermotic,  definition  of,  335. 

"         foundations  and  uses 
of,  360. 
Thinking,  six  things  necessary  to, 

36,  37. 

Thinking,  source  of  errors,  37. 
Thoughts,  relations  of,  419-425. 
"         two  kinds  of,  419. 
"        four  laws    of  natural, 
419-423. 
state-  Thoughts,  arbitrary  relations  of, 

423. 
Thoughts,  mnemotechny,  423. 

"         means  of  widening  the 
range  of  relations  of,  424. 
222  Time,  principles  relating  to,  53, 54. 
Torture,  its  effects  on  testimony, 

218. 

Toxicology,  definition  of,  336. 
Tradition,  remarks  on,  401,  402. 
Translations,  particular  use  of,  208. 


4C8 


INDEX. 


Truism,  eight  forms  of  it,  52, 
53. 

Truisms,  definition  of,  52. 

' '        general  expression  of,  52. 

Truth,  general  criterion  of,  45-48. 
"  common  error  in  investiga- 
ting, 119. 

Truth,  two  extremes,  1 19,  120. 
"      their  common  origin,  120. 
"     proper  course,  120. 
"      requisites  to  discovery  of, 
120,  121,  261-266. 

Truth,  frequent  causes  of  failure, 
120. 

Truth,  proper  and  improper  hab- 
its, 121-127. 

Truth,  how  former  to  be  secured, 
127. 

Truth,  necessary,  29,  31,  32. 
"      contingent,  31,  32. 
"      hypothetical,  31,  32. 
"      universal,  how  known,  52. 
"     what  requires  no  proof,  127 
-129.  ' 

Truth,  prerequisite  to  its  admis- 
sion, 128. 

Truth,  what  may  be  admitted  as 
proved,  129-134. 

Truth,  what  requires  formal  proof, 
134. 

Types,  organic,  242,  243. 

U. 

Ultimate  causes,  definition  of,  170. 
"  "  what  alone  are, 

170. 

Ultimate  causes,  error  regarding, 
170. 

Unconditional  proposition,  defini- 
tion of,  39. 

Uniformity  of  nature,  how  known, 
101-107. 

Units  of  measure,  87,  346,  355, 
357. 

Universal  belief,  aberrancy  of,  316, 
317. 

Universal  proposition, definition  of, 
39. 

Universal  truths,  only  means  of 
knowing,  29,  31,  32. 

Universal  truths,  various  expres- 
sions of,  64. 

Usages  of  language,  how  learned, 
204. 


Usages  of  language,  how  employed 
in  interpretation,  203-206. 

Usages  of  language,  which  the 
best,  and  which  good,  386,  387. 

Usual  signiii cations,  when  to  be 
adopted,  201-203. 

V. 

Vagueness   of  expression,  means 

of  avoiding,  191-198. 
Vagueness   of  expression,  sources 

of,  196,  197. 

Various  readings,  sources  of,  234. 
"  written    and 

printed  copies,  234. 
Various  readings,  rules  regarding, 

232,  233,  235,  236. 
Various  readings,  general  charac- 
ter of,  236. 
Varying  probability,  sophisms  of, 

304-306. 

Velocity,  principles  regarding,  59. 
"        actual  and  virtual,  Note 

23,  443. 
Verbal  definitions,  nature  of,  192. 

"  "          rules     regard- 

ing, 192,  193. 
Verbal  illusion,  aberrancy  of,  314, 

315. 
Verification,  various  methods  of, 

90. 
Vernacular    language,  how    first 

learned,  85. 
Vicious  circle,  paralogism  of,  268, 

269. 
Visible  representations,  uses  of,  91, 

92,  426. 
Volition,  definition  of,  62. 

"         principles  regarding,  62, 

63. 
Volition,  error  regarding,  Note  11, 

438. 
Volition,changes  caused  by,  75-79. 

W. 

Weights,  standard  of,  87. 

Wisdom,  requisites  to,  16,  17. 

Witnesses  (see  Testimony). 

Words  (see  Expressions,  Lan- 
guage, and  Terms). 

Writing,  origin  and  spread  of,  Note 
12,  438,  439. 

Writing,  uses  of,  141,  142,  148, 
228,  426,  427. 


INDEX. 


469 


Writing,  retention  of  knowledge 
by,  427-429. 

Writing,  common  error  regarding, 
433. 

Writing,  means  of  rendering  avail- 
able, 433.  . 

Written  testimony,  remarks  on, 
227-237.  (See  Testimony.) 


Wrong  expression,  paralogism  of, 
277,  278. 

Z. 

Zoology,  definition  and  divisions 

of,  336. 
Zoology,  foundations  and  uses  of, 

364,  365. 


THE  END. 


OVERDUE. 


LD21 


_100m-12,'43  (8796s) 


YB  2306 


THE  UNIVERSITY  OF  CALIFORNIA  LIBRARY 


